Nice big umbrella you are trying to create. there is no, nor has their ever been anything resembling a government in Afghanistan, and 'the Taliban' is an idea, not an entity. It's all warlords, tribes and fiefdoms in that part of the world, each pursuing their own interests.
And it certainly isn't 'revisionist history' when it was obvious at the time to anyone paying attention, but please keep buying into the manufactured scenario they tried to sell to everyone painted with the biggest brush possible and all tied together in a nice neat bow.
Saudi people with Saudi money, the location of SOME of them at the time seems to be the minor factor in the equation. They could have picked Yemen, Somalia, the Philippines, etc. etc. etc as a base with sympathetic people willing to lend em a few acres and a hut to hang out.