I know this idea started as a bit of a joke to counter Matt’s predilection for putting his cavalry in the woods (although Russell Crowe did it so it must be true) but we should tread carefully if it is being considered seriously. I am not sure of how much historical evidence there is for ‘normal’ skirmishing troops engaging in melee combat with formed units. Undoubtedly it happened over the thousands of years covered by the rules but do rare occasions justify making potentially significant changes?
As the Man on his horse, behind the tree, equally the rules on skirmishers might be a little too rigid. After all Skirmishers are used to represent Alexander's expeditionary forces but those very same 'skirmishers' are extremely capable front line troops most days of the week. Roman Velites, Greek Euzenoi are other examples of troops that might be more than their sum in MeG currently. Then there is just tactical balance, it enriches in the game, makes it less of a passive threat more one to be properly considered and factored against. After all the above honourable mentions are really not close to cheap troops for their limited use.
We are potentially only talking about 'badly affected' so everything, bar loose order foot, in Difficult going and rather less in rough going . In MeG skirmishers can attack tugs near to breaking in the open , which if I were a skirmisher, is a situation that seems far more worrying than rushing a intact cavalry Tug in a forest.
and for the majority of skirmishers its still not the greatest of ideas. Short spear cavalry in a Forest is going to be 1+ ssp, +1 foot moving +2 fighting skirmishers, probably another +1 for combat shy and/or poor as well. so a range of +4 to +6
The skirmishers, +3 for fighting badly affected troops.
Cav are still up against your universal basic skirmisher, who break on 1/3 losses.
However throw in some of the better skirmishers , with Ssp, ME or are superior/protected and it gets significantly better.
the cost of good skirmishers, the likelihood of catching enemy tugs in such badly affecting terrain and the reliance on terrain actually sticking to the table rather makes it feel it'd be an occasional nuance to a game, much like skirmishers charging badly damaged Tugs is now.
regards
Matt