If you group 3 or more assault boats offshore and give them a LZ on a shoreline (say 500m away) to move and unload to then they spend far too long sorting themselves into a formation (if given one) and seem to want to space themselves almost 100m apart while travelling to shore.
I have tried starting them in no formation and all possible formations, but each time the last boat won't even start its engine until the lead boat is nearly at the shore disembarking its passengers. Meanwhile boats between the lead boat and last boat constantly throttle off to near stationary speed to maintain what seems some rigidly set AI distance between boats before momentarily throttling up again for a few seconds to catch up some lost distance. This causes a constant up and down stuttering motion and throttle sound, which is lame realism and increasingly annoying to listen to.
The only workaround/solution I've found is to place them down un-grouped. So, if there is a rigid set distance to maintain for AI controlled boats can it be changed to allow a min/max buffer of 20-60 metres between boats please.