I don't think it illustrates it well.
Snipers ARE killed basically immediately in a fight. EHP shows effectively that they are squishy as intended. There are some other factors such as camouflage and extended sight that would allow a unit to have less EHP than an otherwise identical unit, but for comparisons within the same unit category they are an okay mark. If some stats are "too low" (whatever that means) for the price of the unit, you can deduce that they need to make up for it in utility. To stay with the snipers: They are very squishy and expensive compared to front line troops, therefore they make up for it with high range, sight, camouflage and insta kills. The EHP correctly shows that they would lose a 1v1 despite being more expensive.
The comparison of Obersoldaten and Commandos is quite off in most cases, but Stormtroopers fit quite nicely into the picture.
Not quite, I'd argue. In a 1v1 between a Sniper and any squad but another Sniper, the sniper wins every single time without taking any damage, assuming it's being used as it should. It's EHP doesnt come into it because the Sniper simply isn't meant to be getting shot. Best case scenario, of course.
Perhaps a better example might be a TD versus a medium tank. Similar story. The idea is that the TD fights mediums where it cannot be touched, or at least is able to output damage to offset it's lower EHP before the medium can retaliate.
"1v1 final destination" isn't a great way to compare units in many cases. Many units are intended to not take "fair" fights. Assuming they are, and getting hung up on EHP, can lead one to the wrong conclusion.
Even in the Commandos/Stormtrooper comparison it's not all that enlightening. Commandos do indeed have higher EHP, as Vipper has stated, but differences in the units' function and abilities make this even more pronounced. Stormtroopers are intended to make themselves much more vulnerable to fight at full performance, with Tactical advance reducing their EHP, and slowing them. Commandos, in comparison, fight at full efficiency merely by beginning to shoot from camouflage, they don't need to become more vulnerable. They also have their Gammon bomb, whereas Stormtroopers have no explosive.
I really just think EHP is too highly regarded when trying to compare units. It certainly is important in 1v1 slugfests, but it's really not the be-all-end-all stat.