AbdulAlhazred
Legend
For this latter bit one can actual make death of the team impact the controlling enchantment or the summoner too not as morale but something else perhaps.... where things unravel faster.
And will battles against the monster are actually you fighting the will which controls them.
Now, that's an interesting take on, at least 'lesser', undead. They're part of some 'controlling enchantment' thus always an extension of the will of someone else. This could also work for summons. It also fits in well with any "you can only control X number of summons/undead/constructs/whatever" sorts of rules, perhaps without the more cumbersome action sharing mechanics of 4e.
Though honestly the action sharing mechanics certainly work very solidly; they are just a bit rigid in terms of you pretty much can't relax them in a very meaningful way even if it would make sense (IE if you wanted someone to have 10 minions under their control. Sure you could slave them all to your actions, but that rapidly becomes quite inflexible, leaving little room for PCs with an 'entourage'). I get that the entourage WAS the problem, but it would be nice if there were more options than just axing the whole concept.
So, maybe the PC with 10 minions (or 10 skeleton minions, whatever) would have to A) exercise use of an action to maintain overall control, so there's still the action economy calculation to think of, and B) be subject to some sort of fairly unfavorable 'morale' concept, and/or possibly 'feedback damage' of some sort, at least in the case of things like undead. A druid might not be made quite so vulnerable when utilizing woodland animals for instance, but then again maybe the same thing applies... In the edge case it would devolve down to pretty much 4e's existing summons rules where you get (generally) one summons and it sucks up your action economy to 'run' it. I think maybe making the actual summoning into a ritual would HELP the situation with summons though. You'd have to anticipate a need, but that really isn't TOO hard. Instead of burning a precious Daily you pay an up-front cost (which might include a surge cost) and then basically you have an extra option to use your actions, moving/attacking/whatever with the summons. Existing 4e summons just really aren't much worth it given the need to sacrifice your daily slots on top of it being simply another action use option (plus a bit of blocking perhaps and maybe a useful instinctive action for some types). 4e summons are not terrible, but they don't tend to be top-notch options.
Anyway, just some random thoughts...