Action Points
Just popping my head in with some information that may or may not be useful.
As you know, Legions of Steel didn't use action points -- all figures received both a move action and a fire action.
However, when Global Games translated Legions of Steel to World War II for their Stalingrad game, they started using Action Points, and the default number for every figure was "3" (NCO's or "super" figures received 4 or 5, green recruits received 2). A "Fire" action required 2 Action Points (+0 to hit), a "Snap Fire" action required 1 Action Point (-1 to hit), and a "Aimed Fire" action required all 3 points (+1 to hit).
You can see how that translates to the same modifiers they had in Legions of Steel...walking was 0 (spend 1 action point to walk and 2 to fire), running was -1 (spend 2 action points to run and 1 to snap fire), and standing still was +1 (spend all 3 action points to aimed fire).
Stalingrad kept the "covering" mechanic from Legions of Steel in that any figure that had action points remaining at the end of their turn were automatically "covering" and a counter was placed next to them. However, the "covering" counter was different from the Legoins of Steel counter -- instead of 0, -1, -2, it says 1, 2, 3, marking how many action points the figure had left. The type of covering fire that the figure used was based on its remaining action points...Aimed Fire for 3, Fire for 2, Snap Fire for 0. The interesting difference between this and Legions of Steel is that Legions of Steel added an additional -1 to hit for Covering Fire, and the Stalingrad rules with action points did not, making Covering Fire slightly more powerful.
Instead of each Action Point translating to a single Move Point, like it does in Snapshot, Stalingrad gave a figure 5 movement points for every Action Point spent. It then had a list of move costs that were roughly equivelant to the Legions of Steel move costs. 1 move point for every inch forward, 2 move points for every inch sideways or backwards, 5 move points to open or close a door, 15 move points to break open a locked door. Interestingly, there was no distinction between "running" and "walking" like there was in Legions of Steel.
So why am I bothering to bring all this up? Two reasons. First, in my own experience, it's a little bit of a pita to keep track of all the action points in Snapshot. You really need to put together a play aid sheet for each game that lists the figures and their action points in order from highest to lowest, and a way to mark them all off as you activate them. This is because they can have so many action points, and this is the reason (I think) so many people hate action points. It occurred to me that the Stalingrad version of Action Points...limiting figures to between 3 and 5...might go a long way to solving that problem. Though, admittedly, the whole "1 Action Point equals 5 Movement Points" might be too confusing. But again, as you know, I like the fact that Endurance is an important characteristic in Snapshot (adding to your action points), so I'd like to preserve Action Points even though in general I don't like them. Maybe this is a way to do it.
The other reason I'm bringing it up is that the real strength of Legions of Steel, in my opinion, was the "covering" mechanic. The fact that *every single* figure was automatically covering at the end of its turn so long as it didn't fire made getting around the flank of your opponent really important, creating fluid and dynamic games, and it broke up the "you go I go" turn sequence. Snapshot already has a "covering fire" mechanic but it's a bit cumbersome and it's not "automatic".
I haven't actually played Stalingrad, so I can't vouch for how successful it is compared to Legions of Steel. I'm not sure that Snap Firing three times wouldn't just always be better than a single Aimed Fire, for example (if you remember Legions of Steel only allowed you to fire once). But, at the very least, I thought I'd write this down as food for thought.