You could also add a card with an effect analogous to what the obstinate baloth does against discard decks (or 'cannot be countered' cards as a different example): offering players the choice of including a card which heavily punishes a very specific type of gameplay over more generally useful cards. This way, if that type of gameplay becomes too prominent, players will add this card as often as possible, until the balance shifts.
I realise this is easier said than done in the case of mono red aggro though.
You could also add a card with an effect analogous to what the obstinate baloth does against discard decks (or 'cannot be countered' cards as a different example): offering players the choice of including a card which heavily punishes a very specific type of gameplay over more generally useful cards. This way, if that type of gameplay becomes too prominent, players will add this card as often as possible, until the balance shifts.
I realise this is easier said than done in the case of mono red aggro though.