Coyotes at 400 yards. I assume they would be the same size as a small Kangaroo or large fox ?

Go a custom mount.

Any quality 'older' Euro scope would do on that Ross. A good Pecar being almost equal to a Zeiss or Hensoldt and a lot more economical to purchase.

I would submit reticle choice and thickness will have a larger impact on long range effectiveness at the lower magnifications mentioned. I have had to practise with some reticles using the top of the horizontal cross hair as the aiming point. If the vertical portion of the reticle is too thick, kiss it all godbye.

A reticle with a pointed or vertical bar may suit you better. Even a flat topped bar that subtends 2 Moa at 100 yards can work well at distance if you practise hoilding off L or R. An added bonus is a less obstructed sight picture.