Robinson has not been able to name an unchanged side for more than a month and was forced into making four changes, due to injuries and international call-ups, for Saturday's 2-1 defeat at leaders Leyton Orient.
"If I was going to be critical of us, I would say we don't seem to have that fluency that we had at the beginning of the season," he said.
"We seem to be a little bit periodic in how we play our football and that's purely down to the players we've had out and the changes we're constantly making.
"People are playing with different players around them and so they seem to be questioning themselves. If you look at the midfield two, it's been difficult for them the last three or four games because everything around them is constantly changing.
"Once we can settle down and get our group together we'll be a really good team. If we had that opportunity to name the same team every week you'd see us in a much different position."