Good question. I'm curious about this as well as I'm only just experimenting with this.
Generally, I still leave it to the AssMan but make the occasional change prior to upcoming games. I do think the standard sessions are a little too generic and, whilst it stops overall stat drop, it doesn't target those important attributes at those low levels. not a dig; just room for marginal gains.
The other problem I have at that level is it takes an age to get team cohesion up to even a moderate level. Poor players playing poorly together: Nightmare fuel.
I've not planned this out exten