Basically its just the mod teams ways of giving the middle finger to Wehr not to spawn Storms out of the building to do something actually useful.
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the flame nade is both odd and not very useful, it can't really kill caches within reasonable time, so whats the point of it then?
You can't have units infiltration spawn at full elite strength because they'd easily wipe retreating squads. This (alongside with direct access to grenade) was removed a long time ago. Commandos spawn with 3/5 models, Stormtroopers spawn with 4/4 models but with Gren rifles. No middle finger, just following healthy game design.
The Stormtrooper flame grenade is specifically designed to take out caches in combination with a bit of small arms fire. This is to prevent instantly killing caches, or would you think it's fair Stormtroopers could just infiltrate spawn from a building, throw a grenade and retreat and kill a 250MP cache without any chance for the enemy to defend themselves or retaliate?