I don't think it's about flirting with form. If you're feeling good, feeling great, you don't need a rest. If you've got a slight niggle, 10 days will probably sort it out enough that you're fresh enough to roll for finals. If they need a rest after a long season, and they've played most of the season, a short sharp training session during the week/15 min warmup on game day is enough to shake out the cobwebs
I don't think "flirting with form" is an issue, because we've played 5 months of no silly buggers footy. Our touch, fitness and game sense isn't going to be impacted by a couple of days on the sidelines between a Thursday and Tuesday training session.
If players are tight or sore heading in to week 1 of the finals, making sure they're fresh is the best way to go. A smash out against a bottom 4 side isn't really going to help us with being up to date with high tempo finals footy. Saying that, playing the Saints is probably close to the best preparation we can get from a bottom 4 side, the Saints lads will want to be up and about to send a non aggressive **** you out to Lyon. I reckon we'll get a solid enough hitout from them to make sure our lads are up to pace for finals.