Guild Wars 2

Astralporing.1957:

Olvendred.3027:

Anet specifically designed Guild Missions so that they could be done by small guilds.

Yes. They did. By their posts at that time, “small guild” was thought by them to be one with below 50 players or so. Guilds in the ~10 active player range didn’t even qualify for consideration.
In fact, putting bounties before treks in the unlock tree was a clear message that they didn’t want small groups to ever get to easier treks and rushes.

You don’t need 50 people to do tier 1 bounties. You don’t even need 10. Back when we were unlocking bounties we did them with 4-6 people. Sometimes we were unlucky and got terrible combinations(sometimes they were great combos, almost finished a t2 once) but that is why we did bounty training for the influence. It would have been easier(most for the searching, having more people can be bad for the fights) with more people but is not an absolute requirement.