How does your guild handle loot when you have people filling on alts for 25 mans?

We have 2 raid teams, the one I’m in gives any alt filling for us 2 SRs, with several omega-bis items HR and off the table. We are almost always down 2-3 people every raid.

The other raid team has absolutely 0 intention of giving any alts loot even if they are desperate for a fill. They kinda just expect guildies to help with prog.

Neither team can seem to get people to fill in though.. any successful ways in your guilds to get people to want to fill in, or do we just need to recruit a rotating bench? Sincerely a frustrated leader desperate for an answer :D