Yes, that's exactly what I want. A trade ship that's fully built should be able to present a credible threat to an attacker, especially once the cops start helping. I think that's what FDev want, or at least wanted, too. Why else do trade ships have weapons and SLFs? You don't need either of those if you're only ever supposed to flee whenever you're attacked. Why even send cops if you're supposed to run right away?
Would you want to use a trade ship for bounty hunting? Probably not, as you wouldn't have any gear to assist in tracking and maximizing profit, nor would you be able to persue a fleeing target as well. Would you want to a combat zone? No, as you don't have any equipment to keep your hull and modules in good repair for an extended sortie.
For a SINGLE engagement, though? A fully built trade ship should absolutely be able to provide a credible threat to an attacker. It makes the game far for exciting and thrilling for all parties involved, introduces more tactical decision making, and opens the game up for far more interesting stories to unfold. There is absolutely no reason that traders MUST be toothless prey with no option but to run, other than people being incapable of seeing past the status quo, or the tropes established by some other games.