Compare 4-3-2-1 vs 4-3-3 vs 4-5-1 Tactics

There has been a lot of talk recently about how Manchester United blew the tactics against RB Leipzig.

I usually play a 4-2-3-1 and fall back to 4-3-2-1 to be more defensive.

I am trying to understand the differences in setup within FM2020

4-2-3-1 setup
Typical 2 in midfield are DLP/BBM with a AP/MEZ setup and then two Wings (IWB or IF) and then 1 central AM/AP with 1 Forward DLF/AF

What I am trying to understand does the 3-1 vs 2-1 vs 3-3 up front have the wingers setup as IWB vs IF or is the difference more subtle or more pronounced?

Or is it just similar and how we state the tactic?

Thanks