These are all great points!
What I have found is that whatever you price a 1 Life squad at, if you bump it to 2 Life, it's new point value should be its original point value times 1.85 (rounded to the neared 5). For example, the Roman Legionnaires (50 points) and the Rhox Veterans (90 points) have very similar stats and abilities. If the Romans were 2 Life, they would be 95 points (50 * 1.85 = 92.5), which is caparable to the Rhox Veterans at 90 points. There are definitely diminishing returns on more Life for squads (which is why it's x1.85 and not x2) because sometimes having that second Life doesn't matter, like in the case of squad autokill abilities or receiving 2 wounds from a single attack.
That's an interesting attempt to reconcile the points:life discrepancy. I am 100% with you that there is diminishing returns on higher life squads for the reasons you have stated - it's easily chewed through when that 3 skulls to 0 shields attack comes through, and OHKO abilities don't even care about life, so it's *absolutely not* a 2x cost multiplier at least for most squads. Have you playtested in Heroscape and found that 1 squad of Romans at 2 life tends to contribute about as much as the Rhox? Or was your conclusion drawn mostly on theory because the two look very similar on paper?
In AotP realm, the Rhox are a *horribly* designed squad. I'd put them as one of the worst squads in the entire game. They are a *3-man unique squad* with an ability that takes their garbage defense of 2 and bumps it to 4 at max, but only if they hug each other in a full triangle, which makes it really hard to also maintain 3 attacks per turn with them and/or split them up for any reason (and forget it if even one of them dies.) I'll get back to the Romans comparison soon, but even within the base AotP set itself there's the 3-man blue Leyline Phantoms (3L, 3A, 5D, 6M, 1R, Phantom Walk) where they cost 95 points, yet are arguably a league ahead of the Rhox simply due to having 1 more move and that sexy base 5 defense versus Rhox base 2 defense with a boosted cap of 4 from their ability. Rhox Vets are gimped af, so much so that the AotP community has literally discussed making a *custom Rhox hero* which would have some kind of move/attack bonding with the Rhox Vets, giving them a turn efficiency buff that they sorely need.
But back to Romans, it feels like the Romans are having a better time than the Rhox because:
1. They are a 4-man squad, on that alone they already have more warm bodies around for shield wall to proc.
2. They are common, so it's possible to have many more of them around especially if 1-2 die, so the capacity of the shield wall ability isn't instantly nerfed, unlike the Rhox.
3. Bonding. Rhox don't have anything like it (I'd argue trample is moderately weaker than bonding, but this only in a "trample is mediocre in AotP, while bonding is pretty good in heroscape" sense/comparison, since I have not playtested these two squads side-by-side at the same time in one game's environment.)
IIRC I'm mostly only overlooking the base 4 move vs base 5 move of Romans vs Rhox, but I still wonder how often the Rhox would actually carry as much weight as 95 pt 2-life Romans, even if we intentionally omit common status of Romans and played them as a 1-of squad. The life boost to the Romans seems significant especially when looking at the perks that Rhox lack in comparison.
Perhaps the more apt test is to take some other heroscape squads that are 1-life and at the 90-100 pt range, and see how Romans do with their 2-life/95 pt card change. This because at the end of the day, AotP and heroscape play slightly differently and points cost between the two probably scales oddly.
While ofc I would never stop you from creating all of your customs using your multiplier to make them multi-life, I'd bet it doesn't scale the same even across all Heroscape squads - I'm mostly thinking of poor survivability squads compared to high survivability squads. Certain abilities would more intensely dumpster or skyrocket a squad's viability as they gained more life, although I think we have somewhat proven that with the Braxas theorem above.
