I would suggest that the following strategy would accomplish much of the same end results, without ANY players being undesirable because of the renown they earn, and would be a lot simpler to implement:
1) Convince the devs to eliminate renown decay entirely. This would benefit all guilds but the biggest benefit would be to small and tiny guilds that have not had any relief from decay yet.
2) If the devs can't be convinced to eliminate decay entirely, then reduce decay by lowering the guild size portion of the decay formula from 20 to min(20,actual modified guild size). This would greatly help small and tiny guilds that are still struggling with decay.
3) If the devs can't be convinced to do any further reduction in decay at all, then raise the small guild bonuses for small and tiny guilds that are still struggling with decay so that those guilds will at least be viable and able to advance.
The main advantage here is simplicity. None of these options would require any new coding. All of these could be achieved with very trivial changes to the decay formula or to the small guild bonus multipliers, much like the initial change the devs made at the start of this thread. Every guild that has more than 10 players in it got some relief from decay from the initial change. It's time we expanded that relief to the tiny guilds that have got none so far.