If I trust them to handle them responsibly, they can shoot all they want until the ammo is gone.
When my family goes shooting together (dad, uncle, brothers, maybe a cousin or two), there could easily be 100+ firearms laid out in the back of trucks, cars, or on tables.
Everybody has a little different taste and variety, and it’s fun too shoot something you don’t have, or something that’s not real common. Want shoot my dads .450 double? Just ask. Want to shoot my brothers type 38 or 99 Arisakas? Just ask. Want to shoot my brothers WWII hand made black market copy of a Mauser(ish) pistol? Just ask. Nobody just up and grabs something, always ask, only time there might be a no is if there is very little ammo, or the gun is having some issues worked out.