Longer macro lenses like 150mm, 180mm and 200mm give you more working distance, but are more difficult to hold steady and render shallower depth of field, which is already in short supply at high magnifications. As a result you have to stop down the longer lenses more, which in turn means slower shutter speeds or higher ISOs. There's a reason 150mm, 180mm and 200mm macro lenses come with a tripod mounting collar!

So, again, in my opinion for general purpose macro a good compromise is the 90 to 105mm range. That still gives you quite a few to choose among. The video linked in this article doesn't cover them all, but might help with some of the choices (a couple lenses in the comparison aren't an option for use on a Nikon camera, and one is manual focus only): https://petapixel.com/2020/04/15/macro-lens-test-canon-nikon-sony-laowa-sigma-and-tamron-compared/" rel="nofollow" target="_blank"> https://petapixel.com/2020/04/15/macro-lens-test-canon-nikon-sony-laowa-sigma-and-tamron-compared/

To me the Sigma 105mm seems the best value. It used to be the most expensive, but the price was reduced significantly within the last year. Now at $570 it's nearly $330 less than the Nikkor 105mm. And the Sigma has among the best images quality and a full set of features.

At $429 the Tokina ATX-i 100mm is the least expensive true macro lens with auto focus available. It's a pretty good lens, with a couple quirks. For one, the Nikon mount version of it doesn't have a built-in focusing motor. As a result, on some Nikon cameras it's manual focus only. This isn't a problem with your D750, because that has the in-body focusing motor for lenses of this type (which also include the Nikkor AF 200mm f/4 and the Nikkor AF 60mm f/2.8D). While this won't effect your use of the lens, it may effect the resale value of the lens should you ever decide to sell it.

Another "quirk" of the Tokina 100mm is that it uses a "focus clutch" mechanism. The entire focus ring is slid forward or backward to switch from manual to auto focus. When it's set to the AF mode, you cannot override and tweak focus manually. You have to first shift it into MF mode. This is not the case with the Nikon AF-S, Tamron USD and Sigma HSM lenses.... all of those allow manual tweaks to focus while still set to AF mode.

Finally, the Tokina 100mm and a couple other lenses are not internal focusing. This means they increase in length when focused closer, which may reduce working distance between the front of the lens and your subject. Other macro lenses that aren't internal focusing include the Nikkor 60mm f/2.8D (but the AF-S 60mm f/2.8G is internal focusing). The older, less expensive non-VC, non-USD version of the Tamron 90mm also was not internal focusing.

Like all lenses, the specification of macro lenses list a "minimum focus distance", but this isn't the same as "working distance". MFD is the distance from the film/sensor plane to the subject when the lens is set to it's closest possible focus. With non-macro lenses this is fine... but with macro lenses those distances are pretty short so it can be significant that some of the MFD is occupied by part of the camera (approx. 1.75") and by the lens itself. When a lens extends a lot at MFD, it occupies more of that space.

Working distance has to be calculated deducting the length of the lens and part of the camera from MFD. What remains is the distance from the front of the lens and the subject at maximum magnification. (Without a hood or any other accessories installed on the lens.)

Price, MFD and approx. working distance for some of the popular options (least to most expensive):

Tokina ATX-i 100mm f/2.8.... $429.... 11.81" MFD... 4.09" working distance.
Sigma 105mm f/2.8 OS HSM... $569... 12.28" MFD... 5.26" working distance.
Nikkor AF-S 60mm f/2.8G... $597... 7.2" MFD... 1.95" working distance.
Tamron 90mm f/2.8 VC USD... $649... 11.81" MFD... 5.15" working distance.
Nikkor AF-S 105mm f/2.8 VR... $897... 12.01" MFD... 5.39" working distance.

https://www.bhphotovideo.com/c/products/SLR-Camera-Lenses/ci/274/N/4288584247?sort=PRICE_LOW_TO_HIGH&filters=fct_a_focus-type_5738%3Aautofocus%2Cfct_lens-format-coverage_3332%3Afull-frame-lenses%2Cfct_lens-mount_3442%3Anikon-f%2Cfct_special-designs_3320%3Amacro

There are other things to consider, such as whether or not a lens has a focus limiter. Macro lenses need to move their focusing groups a long, long way to go from infinity to 1:1 magnification a few inches in front of the lens. Also, most macro lenses use a "long throw" focus design that emphasizes focus accuracy over focus speed. The limiter can help the lens perform better in some situations. For example, the Sigma 105mm has a three-position limiter with one setting that gives the full range of focus, another that's non-macro distances only and a third that's close-up and macro only. This can be a useful feature at times when you're shooting only macro... or using the lens as a short telephoto for only non-macro purposes. Check the specs on the other lenses to see what they have.

"... Then the person giving the talk cropped the wide angle shot to the exact dimensions of the telephoto shot and the photo looked the same as shot with the telephoto lens..." Really? If taken from the same exact position and you zoom in one to one on both the wide angle image will likely have the pixels clearly visible...

So that may work well if you're after the effect of the French Impressionist like Monet... but try and submit that for publication and you'll be the laughing stock of the editors office...

Get over it... Telephotos are used for portraiture for compelling reasons... show me a portrait photographer using ultra-wides and I'll show you a staving artist...

We are talking two dimensional art here... where optical illusions are the rule NOT the exception.
https://nasco-education-blog.com/2018/01/25/the-science-of-optical-illusions/

Getting so tried of these endless debates over a silly visual paradox...
Maybe get out and try to make money with your wide angle optics, Mike?
Other than for real-estate commercial shooters they are are oddities for enthusiast.

btw, I'm a major fan of Nazareth PA Mike... been playing my Martin guitar for decades.
Martin's factor in Nazareth PA is the epicenter of six string design... and has been since before Moses parted the Red Sea... All the best on your epic journey Mike :)

"Longer macro lenses like 150mm, 180mm and 200mm give you more working distance, but are more difficult to hold steady and render shallower depth of field"
Fact: Depth of field at any given magnification and aperture will be the same, regardless of the focal length.
"Finally, the Tokina 100mm and a couple other lenses are not internal focusing. This means they increase in length when focused closer, which may reduce working distance between the front of the lens and your subject."
Fact: An internal focus lens will provide less working distance than an external focus lens of the same focal length.

However the result of perspective change at magnifications of 1:3 or less using camera shift yields greater distortion than focus breathing at that magnification. See an actual comparison of the results of the two methods by the author of Zerene software, Rik Littlefield. The software has less problems with the size change created by focus breathing than it does with the changing perspective created by moving the camera on the rail. http://zerenesystems.com/cms/stacker/docs/troubleshooting/ringversusrail.

added: This is true at least using Zerene Stacker software. I have not tested it with Helicon or Photoshop