I've been using them since the last FM21 patch and current patch on FM22, nothing really changed in the tactics, just a nuance in the 3-4-3 with the WCB. I do not recommend using the WCB in this 3-5-2, only in the 3-4-3.
3-5-2 (main one)
Some guidelines for some positions (VERY IMPORTANT!)
GK - Good Long Range Passing Ability
WB(R)(L) - Pace, Strength, Resistance, Dribbling, Crossing, Good Defensive abilities all round
CD - Tall, Strong, Pace, Good passing ability
DM - Tall, Strong, Pace, Good passing ability
CM (L) - He's your number 8, the lung of the team, he needs to fit the needs of a box-to-box midfielder, the reason why I chose the generic CM role instead of the B2B was that in some matches I need a more creative player in that position and a generic role lets me play more with players traits and profile.
CM (R) - He's your creative outlet. Pace, strong on the ball, good dribbler, passer, crosser, you can even adapt a winger in this position if he has the mental stats for it. (These are the ones who will also play behind the striker in the 3-4-3)
CF - Like the role suggests, he's complete, needs to be good on the ball, but he also needs to have a good physical ability, not only is he important in providing precision and decision making moments in attack he also provides alongside with the AF a strong first press (Doesn't work so well in FM22, although the latest patch did find some improvements as we are being able to create problems again with the press)
AF - He and the CF will be making a lot of counter movements, making the defenders "dance" from position. The AF is a strong, quick and physically imposing player, tall, and with the plus of being a decent crosser at least since he is going to be making a lot of movements on the wing, trying to stretch that defensive line.
I use the 3-5-2 against teams who use an offensive mid.
3-4-3 vs 3-4-3 or 4-3-3
3-4-1-2 vs. 4-4-2 or lower league sides (switch back to the 3-5-2 if the opponent is causing problems)