With the recent BOLS article on the winning list from NOVA we're once again seeing that 40k seems to have a bit of an issue with blob units pared with morale-boosting abilities. Whilst some might say that Orks, with Nobz and Mob Rule, and Chaos, with Dark Apostles, are too good at keeping large units in the fight and immune to morale (I would tend to disagree) the outright leader in the field are Conscripts paired with a Commissar. For a low cost, this combination allows a 40-strong blob to soak up a ludicrous number of casualties and still only lose one model to Morale. As with most things in 40k, this isn't necessarily a problem on its own, but if you start seeing multiple units of Conscripts, all being buffed with Orders and all being basically impossible to get rid of, it starts to look like an issue.
Have Hat, will Inspire
So, let's firstly look at how a Commissar works, and what he's meant to be doing. The Commissar, or his HQ equivalents, all have a 6" bubble of Leadership (8 for basic, 9 for Lord/ Yarrick). They also have another 6" bubble within which ASTRA MILITARUM units only lose one model if they fail a Morale check. This, let's remember, represents the Commissar shooting a member of the unit, making it clear to the rest that they'll get the same if they run.
The first issue I'd raise here is that the range of both bubbles is the same, which makes the Morale buff almost irrelevant in the Conscript case. Since 6" is half the effective range of a Bolt Pistol and a Commissar is a BS 3+ model, it seems a bit of a stretch to have him able to pick off a fleeing trooper (who we can reasonably assume is trying to avoid him) at that range. So fix number one that I would suggest is this:
Fix #1: Reduce the range of Summary Execution to 3".
Make the removed model the one nearest to the Commissar.
This also leads nicely into the next point. We know that a model with a Bolt Pistol can usually only fire it once per turn. The Commissar is already 'firing' out of his own turn but this presumably exists in the same temporal bubble that Overwatching units use, so we'll let him skate on that. But there's certainly no reason to assume he could, er, 'encourage' multiple units at once- there has to be a limit on how many is reasonable. So fix number two would be this:
Fix #2: Limit Summary Execution to only affect one unit per player turn.
With these two tweaks, we still maintain the ability of a Commissar to do his job without allowing him to hold an entire army in place single-handed. We still have the issue of Conscript units being almost impossible to remove, since 40k now has far less attacks that hit all members of a unit or all models in an area. For the third tweak, then, we need to reduce the effect the Commissar has on big units without removing his signature ability. I would suggest the following third fix:
Fix #3: Summary Execution reduces the number of models lost to Morale by the Leadership of the Commissar, to a minimum of 1 model.
I think this one is pretty elegant. For a standard-sized squad, it leaves the ability basically unchanged- even a base LD 8 Commissar will prevent a standard Guard Squad losing more than 1 man to Morale, just as the God Emperor intended. But for a 40-strong blob that should lose 15 men to a single test, the Commissar would reduce that loss to 7- still a lot of guys, but a fair level of mitigation.
I wouldn't necessarily advocate applying all three of these fixes- #3 might be enough on its own if the biggest issue is perceived to be that Conscripts hang around for too long, rather that the ability of Commissars to hold multiple units. I'd be interested to hear the thoughts of other players on the matter.