I actually gave 5 of my larger chickens away yesterday they were either barred rocks or dominiques but it got a HUGE rooster and 4 of his hens out of the pen..... I put them out in a temporary run and two (roosters of course) kept flying over the fencing. They didn't head to the porch, more like down near the clothesline (following under our trees around the fence line). They seemed to really like just the little extra room, or the green grass.
Since you removed the likely alpha rooster your two wondering roosters will likely feel mare at home in the pen.