Why welcome fake Hugh & Amir to the house even after knowing they are impostors?

Firstly, there is nothing like "real" Hugh and Amir. They were from a different thread of reality. The band aid Hugh had this time(the script you shared) was a normal band aid. True. But this doesn't suggest that this Hugh and Amir is not from this house. It merely suggests that, the previous Hugh and Amir(The Hugh who got a cloth band aid from Lee) and this pair are not same. If you follow the continuing scene, it shows they show their blue glow sticks and the red glow sticks they took from the other house. Thus the glow sticks clause is more plausible, than the band aid. The conclusion?---Lee tended to the wound of one Hugh who did not belong to that house. Track back to the scene when they start talking about a book and Laurie says "Some actors read!"? Just then we see Hugh and Amir talking sort of privately realising that this house is not originally theirs. they are in the wrong house.Now this Hugh, you would notice has a cloth bandage, possibly the one which Lee gave to Hugh. One mistake I made when I watched it for the first time? I though the base house (first) was always constant. But you need to remember the house and the parties are also different. This proves the concept of the Roulette Wheel, that dark area through which, if anyone passes they wouldn't end up at their original house, just one of the many houses. Thus we see there are more than two houses. Whenever a quantum coherence is occurring, that is characters from different realities are interacting..this roulette wheel goes for a spin.

Hope this answers your question as to why they welcomed them this time, as there weren't any doubt after seeing the blue glowsticks and the red glowstick bag was unopened.