but conversely, thats my point. if it was an event that said: if your uruk-hai wins a skirmish, discard a possession born by the character it was skirmishing, ok, fine. but as it stands, the planets would have to align for your version to be useful.
1. its an event, so you have to have it in hand.
2. an uruk has to win a skirmish, not SO hard, but if you are actually playing a decent opponent, there is no guarantee that you will win a skirmish during the turn you draw the card. thus, we have the hand clog problem you mentioned.
3. now that we have won the skirmish, we actually have to WANT to not assign wounds during said skirmish. with most uruks being damage +1, and the trackers who DON'T have d+1 actually like the possessions on the comps, there is no sure bet that you'll want to dis a possession instead of dishing out the wounds.
4. There actually has to be a possession or artifact on said companion. which is hit or miss depending on format, and meta.
so all in all i'm betting that version would never see playtime. perhaps it would if it read: discard all free peoples cards born by the character it is skirmishing. which would have more flavor actually, and give it a chance to see some play.