how is that thinking flawed? fluctuating values don't usually end up as reliable as you think. considering your hp has to get to dangerous levels to even get full effect, you'll likely be sitting at around the same value a L Assault could get... or less if your HP is higher but that's considering you have the pride weapon max skill lv compared to the assault weapon at max skill lv... but the typical strat is to go grind out SR weapons with assault so pride tends to have the edge against those between higher stats and the effect likely averaging out to be better than the SR weapon
but that's assuming you have the pride weapon maxed out... cause not everyone has them at 4 star (hence why i mentioned the current rematch, cause a lot of players likely have lv100 or less on the pride weapons). but again, that's an assumption and not a fact...
if someone really has to squeeze out a pride weapon for the "extra assault value", it's likely a newer player. but for those that did farm tons of assault weapons be it SSR or SR, their grid is probably already optimal on assault value anyway
i still think it boils down to preference. nothing more. cause i don't remember calling the pride weapons bad, i remember calling them situational. i'd rather choose to have a grid full of 13%-16% assault weapons over an unfinished grid that has about 4-7 16% assault weapons, and one that fluctuates between 10%-30%... cause the one cranking out more consistent damage output is more reliable
besides, it's already been established that the trick to playing this game isn't to go after the most possibly OP stuff you can think of (but kudos if you do get it). the trick is getting strong enough to survive the content, THEN going after stuff to get stronger. cause what you're saying is that i probably should fill a grid with 4-5 fluctuating pride weapons if we get to that point, over the raw assault increases. even then, you can't have the viewpoint of an endgame player if you haven't got the power or resources to do such a thing...
plus, keep in mind what a pride weapon actually does. the pride effect can range from no increase at full HP, to 19% more assault at 10% HP left... the raw increase is half the skill level so it's not too noticeable until you get a high skill lv to begin with... so even if it does have 2k-2.2k atk... 1.5% or so isn't much... you'll need to do a suicide setup to really get the power of a weapon like that anyway and a lot of fights will outright shave chunks of HP off you anyway (some fights outright kill someone off if you don't play your cards right and it's worse in a raid where EVERYONE effects the fight)
also, i hate how much RNG can screw someone over... but that's just me