Regarding initiative, the 'side initiative' that Larian is using is actually an alternate rule in the DMG, and the alternate rule is specifically called out being 'unbalanced'. Normally, all the participants roll and everyone goes in the order of highest to lowest. I do remember re-rolling every round back in AD&D, it definitely added an interesting component to the combat.
Team initiative, while not standard 5e, will do a lot to speed up combat. One of the downsides of DOS:2 multiplayer was waiting for your teammates to go, then the enemy, then you...etc. All players being able to move and act at the same time will help the pacing imo.
Though I was also skeptical first about Team/side initiative, after reflecting on it, I also see the bonus of speeding up things. After thinking about it, it is not even immersion breaking. Heck most movie battle scenes work with team initiative. You could still balance it by adding additional rules like, players who roll lower initiative like the mob do have to skip the first turn. Setting up a combat surely should help you having all PCs acting first. And although it might be unfair for poor monsters to mostly act second, i guess that's mostly the case when some fellowship approaches "guarding monsters". You spot them, you setup up the fight to have the advantage to surprise them. Certainly there should be some ambushes the other way around, where our clumsy group of adventurers find themselves trapped and have to watch these nasty creatures to act first....
