The Rossoneri kicked off proceeding with a 4-1 loss to Lazio on Sunday but hit back to beat Austria Vienna 5-1 in the Europa League.
They sit down in seventh place in the Serie A standings but are only three points adrift of table-topping Juventus.
Montella admits that his team is a work in progress and one that is still trying new formations, but the former Sampdoria boss feels the improvement against the Austrians was more down to hard work than any strategic differences.
"People give too much importance to the system," he said. "The whole approach was different in Vienna, with the mentality of a side that was hungry and wounded. The ball moved quickly and that was what impressed me.
"We are working on a three-man defence but that was also true for much of last season. Leonardo Bonucci’s history shows he can play with both three and four at the back.
"However, Alessio Romagnoli is our only left-footed centre-back and that affected my decisions early on when he was injured."