- How about if halve of the chakra the Edo summoning uses for Ninjutsu, gets reduced out of the summoner's chakra pool? The only advantage to Edo Tensei would be the variety of ninjutsu that would be available to you.
If anything, for a different nerf, have putting Edos on the field put a strain on the user. This would make people use it more like the manga, and have their zombies fight for them while they watch, instead of summoning the zombies and having yourself join in on the onslaught.
I don't like either of these ideas just for the fact that neither tend to make much sense to me in my head. Edo is a trump for a reason, and what happens if one summons the max of Six Zombies? If you half your chakra pool for Jutsu and such, six times, after summoning six zombies.... Or even one zombie. You are at 90% after summoning, then you have to half that for jutsu uses and such? That takes you done to 45% right there, stopping you from logically having any more zombies than one or two.
As for the physical strain, although I understand the fact of trying to add some sort of drawback, in a Bijuu fight, or any fight, stepping back and letting a zombie would be meaningless since the fact of the jutsu, more or less, is to give the edge to the summoner in the end.
Regardless, that's just my two cents on that...
I'd also like to ask this;
What about in your own village? For example; If I have four zombies that are dressed like ANBU for my village that simply 'prowl' and such like any other ANBU, is there a rule against that? Already summoned, and just acting like any other Shinobi, obviously them being on auto... Is there anything against this? Or is this allowed?
Edit: In retrospect, that seems harder to implement, perhaps just add the 10% rule to the list we have and be done with this.
^ That.