well going on to 500mg of test a week is not going to help you if you get gassed easily. remember test increases water retention and blood pressure quite a bit.
you are just throwing numbers out to things instead of working based on your bodyfat.
what do fighter need to be? strong, but not massive interms of weight and size. So yes winstrol would work in this area but is forever known to give you issues with joints.
12% you would see full 6 pack abs, i would probably put you at 15-16% most likely.
course recommendation :
start at say 5mg per kg(450mg per week) , and over 8 weeks titrate up to probably 8-9mg per kg.(720-810mg per week) and stay there for 8 weeks before coming off (16 weeks total)
keep your testosterone at 2-3mg per kg, max 3mg. so start at 200mg-250mg.
add in a dht-derived substance that can be run for long period of time ( eg : Primo or masteron)
so say 250mg test, and 200mg primo for 3 weeks, then go up to 250mg test and 300mg primo for 3 weeks, then 250mg test and 400mg primo for 2 weeks.
then run 250mg test, 400mg primo and 30mg anavar/winstrol daily(210mg per week). (total 860mg per week)
add in 200mg injectable L-carnitine pre-training and even 10mg of cardarine daily, to aid in getting you more balanced for fighting.