It depends how the 4-3-3 is played as three strikers can be played if the 4-3-3 is aimed at passing through the middle, the strikers would have to link up with each other and obviously be fairly close in position to do that. The other option could be finding a forward like JET who can naturally play on the wing and cross the ball into the box and play an out wide 4-3-3, how many strikers have you seen can cross the ball and are pretty pacey.
Joe Bryan and Wes Burns are the closest thing we have to developing wingers, although under SOD we did play JET on the wing and with a 4-3-3 if i remember. The ball ended up mostly in our own half and the defence cost us, 4-3-3 is a difficult position to defend if you give the ball away.