How many active skills on average do classes use in Titan Quest?

I recently purchased Titan Quest on my phone (it's the base game with no expansion masteries) and I was wondering which builds are most affected by mobile gaming. The mobile version has 8 slots for active skills (buffs/attacks) and a standard attack, which I believe can be replaced with another melee skill (so possibly 9 slots). How many active skills do builds typically use? Or more specifically, are there any builds that require cycling between more than 8/9 skills often?