Robber Screen or Move Robbers

Three days ago I set up a queenless nuc to attempt to use as a Cell Starter/Finisher. The next day after grafting I found them being raided by robbers (initially opening was about 2 inches.) I closed the entrance off with #8 hardware wire for 24 hours then opened them back to about 1/2 an inch. They were doing fine the rest of the day until the next late afternoon when the robbing frenzy began again. So now the hive entrance is completely closed again with #8.

My initial questions are: 1. Should I leave them closed up longer than 24 hours? I made a robber screen to put on when opened with a 3/8 inch entrance on one bottom corner and a 3/8 entrance on the opposite top corner. 2. Should I move the robbers? I dusted them with flour and quickly found which hive they belonged too. 3. Should I use the robber screen and move the hive? My 4 other nucs and 1 full size hive were all calm while the robbing was taking place.

Additional information: I'm in a dearth period but feeding all hives. The offending robber hive had sugar water at time of robbery but was greedy. The queenless cell starter/finisher hive is on the weak side for raising cells, but I would consider it healthy to strong otherwise. My nuc being robbed has a deep hive body over a screened top to keep robbers away from the feed bottles. My other hives have quart jars on top of a migratory top with 1 3/4 inch hole.

Thanks in advance for your help.