Unit 61, despite having more members than Cassian's team, was clearly the weaker bunch—not because they lacked skill, but because their leadership was... let's say, in need of improvement. Cassian wouldn't call himself some kind of tactical genius, but at least he wasn't charging headfirst into rat hell without a plan. Unit 61, on the other hand, had definitely been doing just that.
Now though, with Cassian stepping in—after his totally necessary, definitely not flashy entrance—they'd started falling in line under his lead. Some of it was probably due to the ridiculous tornado move, and some because Cassian's own teammates were just... easier to get along with compared to Simon's group.