So what? Whatever the means, are the ends really so important?
Fellowship participation in Fellowship Adventures is wholly independent. Fellowship 1 can not make it harder (or easier) for Fellowship 2 to progress. Production costs don't change. Badge costs don't change. The pool of badges don't run out. Map Waypoints don't get blocked. Badge requirements to claim Waypoints don't change.
No, the only point where Fellowships 'interact' with each other, and where Fellowships can get differential rewards, is based on the leaderboard of overall Fellowship Adventure progress. This is a comparison of relative advancement, again in a circumstance where Fellowship 1 can not influence Fellowship 2's score, only their relative position based on better or lesser progress.
And all for what? A higher rank. So? Why do you want it? What does it get you?
Are you being disadvantaged by not getting a few more Perk Points this week?
Are you being unfairly robbed of additional Time Boosts?
Are those special buildings for the top 20 Fellowships that much better than buildings you can build, craft, or win in events?
Is there some other advantage that a higher rank on the leaderboard provides that I am not seeing?
If you want me to feel aggrieved, if you want me to be upset by 'cheating' Fellowships swapping in 'ringer' cities, then you need to convince me that they are 'stealing' something of worth.
So, what are they taking from you?