abirdcall
(she/her)
1. My experience suggests that moving away from an enemy is frequently useful.
Please explain. Most enemies are able to move. If they aren't and have no ranged attacks you could just kill them at range anyway.
2. Mobile costs 1 attack(kindof, you still actually get the attack, it just might not be on your optimal target) to move away from one enemy. Disengage costs 2 attacks(you can't flurry) to move away from any amount of enemies. Mobile will often be enough, but you still have Disengage for when it isn't. I've already acknowledged that in this thread.
Disengage is a red herring.
3. I've also noted in this thread that as time goes on, Mobile is required less(though still useful, as it doesn't cost ki). The Open Hand monk's push ability is a pretty sweet disengage.
Over time? You mean the 3rd session of the game? Levels 1 and 2 only require 1 session (or less) each.
4. Having two good front line tanks(or one REALLY good front line tank) is not a guaranteed win. It is a situation where hitting and running is your best defense though. I wouldn't waste a feat in a non-challenging game on Mobile, as I could just facetank everything without a care.
How do they stop the enemies from fighting other characters? How do they, themselves survive? Chain plus Shield is AC 18. Monks start with AC 16. By level 5 they will have Splint or Plate for AC 19 or 20. Monks will have AC 17. It's really not that much of a difference. In many groups the difference won't even be that large. Switch a sword and board fighter for one with a heavy weapon and now they have the same AC.
Any fight where 1 character can make all enemies attack them and also withstand all of those attacks is not a challenging one. In such a circumstance it doesn't really matter what the rest of the party does.
All the strategies given for Mobile enable is (even it even works - most enemies can just move to the Monk on their turn) to have the Monk be the last character to die in a TPK.