Typical 4-3-3, for me, is with 3 midfielders, 2 wide forwards and a ST (4-3M-3W). Wide forwards who can also play as wingers are way more variable.
Having 3 STs can also be a typical 4-3-3 for some and also is right actually, though in TE 4-3-3 with 3 STs is very rare among managers due to its inflexibility and/or high acquisition cost.
MC-positioning can make or break a team setup alone. Learned this the hard way.