If Lagging Tail is in play, Stall is irrelevant for that match up. Pokemon holding Lagging Tail or that have Stall or that have an activated Quick Claw completely ignore Trick Room.
Within a priority, it goes something like this:
Lagging Tail > Stall > (Normal moves) > Quick Claw
What's in parenthesis is what interacts with Trick Room. Stall Pokemon with an activated Quick Claw completely ignore Stall (meaning they go ahead of another Pokemon with Quick Claw if they are faster). Stall Pokemon with Lagging Tail also completely ignore Stall (meaning they go after another Pokemon with Lagging Tail only if they are faster, and no this isn't a typo).