One thing that should be interesting to do would be trying to get 2 3rd party gangs to share one territory and I think is possible to do so in Little Mexico or El Corona. I once managed to take over these territories from Vagos before doing Los Desperados and then I let Ballas take them. After doing Los Desperados the little GSF these territories had gone, but the ballas remained and thus i got VLA mixed with ballas in these territories, but no grove, and even killing some ballas i couldn`t start a war (i think it is because VLA had higher than ballas).
Now I think, if before doing Los Desperados I put some 3rd party gang instead of the ballas, i think that after Los Desperados it will have the 3rd party gang you chose and VLA. And even better, I think that if you put a 3rd party gang there and then let ballas attack there to gain some density as well and after that doing Los Desperados you will have Ballas, VLA and the 3rd party gang you chose.