I was at Yellowstone with my m43 camera pointed at a wolf. It had a 100-400 mm lens. The woman next to me and a full frame Nikon and a lens the length of my arm. She felt sorry for me with such a tiny camera and lens so offered me a peek at the wolf in her camera. I looked, smiled and thanked her because I had never looked through a lens that big. Size does matter! A few minutes later the wolf moved. I was shooting 4K video so the "crop factor", "angle of view" or whatever is different again. I offered her a look in my viewfinder. She was pissed because my viewfinder had more wolf in it than hers. I didn't even try to explain crop factors or equivalent views.

After the wolf left, we packed up. She had a large man to help carry her gear to her Suburban. In the back was a false floor. Beneath it was custom cut, foam lined compartments for he "wildlife" kit". Mine when into my camera bag.

If there is a point, mine would be to stop calculating and look through the camera and lens. If it is working, use it. If not get a bigger or smaller lens.

My friend, Al, told me this just last Sunday. He works for a medical imaging supplier. Back when one of the companies they represent used Hasselblad cameras as part of their equipment. When they had any problems they sent the cameras to Hasselblad USA. Then they found that Hasselblad was sending them to a guy in Valley Center, KS just north of Wichita (where Al is based). The guy running a one man shop was THE expert on Hasselblad cameras. They got faster service and saved shipping by going straight to the source. Al said he was a great guy to deal with and gave them many good tips on the cameras that no one else did.
My point? Don't forget the local guys when you go looking for service. You might save some money and maybe even make a new friend.

Rick