I suspect when TSHTF, the zombie inner city hordes and the “new” illegal hood rats will not unite as a powerful aggressive force against white folk neighborhoods. These groups will likely be fighting among themselves, rather immediately, as they settle scores, compete for in-close home territory expansion, and attrit one another in the early days. Just their nature; genetic; unable to think strategically; fetal alcohol syndrome all grown up.
That will delay outgoing attacks, reduce their numbers and ammo, deplete fuel, dis-unite their groups, limit their potential range of expansion… for a while (days? weeks? months?). Eventually, strong warlords will emerge. They will likely have degrees of mil background and be quite a bit more intelligent than their followers and have some knowledge beyond the hood. But their efficiency and effectiveness will hopefully be limited, but that is nothing to rely upon.
They will initially rule 5-10 miles beyond city center. Suburbs will be easy picking as the majority of resisters who dare to remain will be weak and stupid. But this is where the groid will gain enough vehicles and fuel to push outward toward the countryside. This is where they will encounter warlords from the opposing side, with lots of firepower and supplies and intimate knowledge of the AO.
The hordes of color will likely not be the big threat. That will come from the multitude of rural warlords and their manpower followers, who evolve from protecting their communities to becoming local despots. Some regions will become like New England 1776; others more like Serbia or Lebanon