The following combination of mechanics:
1. Beastmen act as settlers and can found cities.
2. Beastmen can also join cities and add population, and their EXP gets added to the city as culture.
3. Doviello cities can, at any time, or under a special civic, turn all population into beastmen and turn all culture into experience for the resulting beastmen. -- in this way, the whole civ gan just get up and move to a new local. Buildings would be lost, but they don't need many buildings anyway.
4. The Doviello palace does not need to be rebuilt, but always appears in the highest culture city, and it will move if that changes.
5. Cities can only work the first ring, but as a result they can be founded closer together.
6. Doviello don't get their own workers, but aren't prevented from getting them as slaves.
I think this combination of mechanics would be interesting to play. You could let a city build up culture for a while and then purge the city for a useful army. Or you can turn a 4 population city into 4 separate 1 population cities.
I don't think it would be wise to let players only remove one population at a time, or else a player would set up a culture making city and then pump out units with more EXP than the alter would give. I do think that this mechanic is OK if the whole city, buildings and all, is lost when all population are turned into units as beastmen are most useful early in the game and if one waited until there was massive culture in the city to turn it into units one would be giving up quite a bit.
One interesting possible strategy for this mechanic might be to have high EXP beastmen settle around an opponents city and overwhelm it culturally.
Of course, one has to look at Doviello culture differently than other civ cultures or else this mechanic may not feel right.
anyway...I thought it might be interesing.