While I liked that Ash caught more than 5 pokes in Unova, It was handled incredibly poorly. Not helped by the fact that he had all 3 starters and Scraggy. So would I want him to Catch that many again. No. I just Don't trust the writers to handle it. Plus adding in Pokes from past teams is just going to chew up screen time that could go to developing his newer captures.
My Ideal situation would be Ash catching at most 7 pokes, giving him a total of 8, rotating 2 in and 2 out. As long as he doesn't have more the 2 of the starters, I reckon the writers should be able to handle the rotation