if you still want to use DMC in 4-3-2-1,
maybe you can put your DMC as forward as picture below,
so he will enter MC zone while the ball is with your team, so it will behave as 4-3-2-1
i will focus on the flank, 1st i will check opponent player whose are the weaker fullback, so i will focus there,
while in live game, i will change my focus through the lowest rating opponent player
i might make all my 3 forwards become 3-ST and focus through the middle if i notice their DC rating turn lower than fullback rating
because of almost equal strength, i will start with normal mentality, mixed pass, both flank or specific flank as 1 checked above,
low press, zonal marking, OFF offside trap
but this is just suggestion, not really sure can win, you don't have to follow exactly.
by the way, i never tried to put DMC to play at MC zone, but i was place winger to play at ST, and was not really bad, he still can score, but that was long time ago, now all my winger can play ST as well