sorry i've not much experience on playing 3-4-3. perhaps, i would attempt to propose that 3dc no arrow; mr/ml red arrow; mentality defensive; counter on; offside off unless you have super fast dc; zonal mark; own half; mixed pass. if no goal in 1st half; amend mentality to attack but be careful though. don't rush all players to attack. btw, does he/she has specialist in his/her team? it makes a difference when you choose your formation. hope this help.