It always amazes me how faithfully they stick to that one fact
...Indeed, so much good came from the early seasons being bold enough to establish strange and wonderful things, even if in offhand remarks. "Concepts" seem to disappear from TNG soon after the third season, the show then flying on fumes or extrapolations. The latter were invariably entertaining, the former just noxious.
But as we see later in the episode, the Pakleds are so stupid that they literally fall for a deception that was even more obvious than theirs.
Which calls into question whether they ever did capture that alien hardware. Perhaps that, too, was part of their deception?
I mean, it's not that they'd be slow-witted or unintelligent, even in the endgame. What they suffer from is a complete and utter lack of understanding of weapons technology
. They can't figure out what a crimson forcefield is or isn't, and they can't figure out whether they have photon torpedoes or not.
(I bet not. LaForge only fiddled with bridge consoles - that may work for turning wimpy tickler beams into mighty death rays, under certain circumstances, but it won't provide your ship with projectiles, warheads and launch tubes. We could assume this was a gamble that paid off: by pretending to install photon torpedoes, LaForge established that the Pakled, no matter how devious, didn't know anything about weaponry - hence the crimson forcefield ploy would succeed.)
For all we know, the Pakleds pilfered alien components that were easily obtainable due to being harmless, and patted themselves on the back for pulling a highly successful heist. Correct on the success, but only if you ignore the sad fact that the loot wasn't worth a penny.