Thats with alt nights are for and how we set up our raid schedule once we are ready to move into heroic.
It can add an extra night (we do Tues/Thurs prog and Sunday alt night) but it’s unfortunate that people are being left behind with how you guys may do it.
But other than suggesting that to your own guild, or just offering to set it up yourself, I’m sure there are pugs looking for same.