here you go, ive only just started so i have not tested these in 10.3 at all, i know that they worked well before 10.2, particularly the 4-4-2. as with all tactics give them time, particularly if your squad is gelling. These are real life tactics and not ME exploiting ones so they are not infallible. play with them for a season and let me know what you thinknw man. I can wait.
not particularly, for me 4-4-2 is the default, i use the other against top teams where my 4-4-2 struggles the 4-3-3 and 4-5-1 have completer forward attack, if he is getting too isolated switch him to support. 4-2-3-1 against arsenal, 4-3-3 sometimes against liverpool 4-5-1 against any good team playing 3-5-2/3-4-3 (normally in europe). but really you can pick one as the tactic of your choice and not use the others at all. i used the 4-4-2 90% of the time including against the very best teams, its a matter of personal choice really
one thing ive noticed recently, united play more possession, their passing has shortened, so you maybe wanna change the passing to shoert in the tactics