A good way to use SP2's activation mechanic "as-is" while still accommodating multiple players is simply to halve the number of leader cards you're using per side, but double (or triple or whatever) the number of leaders who activate on that number.
A good way to use SP2's activation mechanic "as-is" while still accommodating multiple players is simply to halve the number of leader cards you're using per side, but double (or triple or whatever) the number of leaders who activate on that number.