If i had 3 years to become a superhero I'd spilt who trained me into 5 parts. Theres 36 months in 3 years. Divided by 5 different trainers, I'd get 7.2 months with each person. So id be trained in this order:
Hit-Girl trains me not to be a wimp, basic superhero stuff, Fighting Skills, and Tactics on how to take down organized crime.
Green Arrow teaches me to become a flawless archer, Fighting Skills, and Survival Techniques.
Punisher trains me in everything about guns, from snipers to machine guns to rocket launchers.
Bullseye teaches me how to turn just about everything into a weapon.
Then after all this training im ready for
Batman! He teaches me, Fighting Skills, Detective work, Pilot, Leadership, and Battle Strategy and Tactics.
Id be pretty powerfull after this. who would you pick to train you? you can have as few or as many as you want. but the more you have, the less time you have with each.