As said, that's a tough request....In order to use a higher power fixed optic much above 2x on close moving targets, you have to train yourself to shoot with both eyes open,,,,even then you will likely just see a bunch of fur, without definition...Your brain is made for optical sensations to be balanced and throwing them too far off really creates confusion...I have tried using a higher fixed power in some action shooting competitions to give me a little edge on longer distance targets (most targets range from 40-200 yards) and it had just the reverse effect...
You will generally have better success with one of the lower multi-power optics...I use a 2.5-10x on my hunting rifle...and keep it set on the lower power,,,I usually have time to crank it up if distance becomes a factor...