I don't even bother training, it's just too expensive
Don't forget, they take up to 12% of ANY profit you make
It is cheaper to hire an expert, I think it's at 150,000 Cr, use him for what ever combat mission you need
then get rid of it, that's how I do it. As for "ESCORT" Missions ? Depends which ships you are talking about
If it's Passenger ships? forget it !! You'd be Space Dust before your escort attacks the Interdicting NPC, they are all Engeneered now and they don't attack on their own, it's 2 or 3 War Ships attacking your ship at the same time