with this Kind of 4-3-3 you can use some different ways. in a normal mode u can use Long or short passing. i would begin with short and after ~20min you can Change to Long, if you didnt get chances in the stats, i got some great results

some words to flat formations: Flat formations are to Play with mixed Focus in most cases! By using aml and amr, you can Play on the flanks. By using aml, amc and amr, you should use mixed focus