Weird - that page mentions Direct3D/D3D twice, but in the list of files only mentions DirectDraw. I suppose that means it can/does use it for 2D, though, which is... strange... It's not supposed to have 2D capacity, thus the graphics card chaining..
I'm not sure you can link a V1 and V2 AND a 2D card together. Maybe you can, but I suppose they aren't made to be used in this way. Doesn't mean they can't be used in this manner though.I've found a documented case of a guy chaining a V1 and V3 together on a Mac:
This indicates to me that my initial theory is correct - if you chain Voodoo cards together they will work fine, and the Voodoo drivers dictate which card gets used based on Glide level (1, 2, 3).
The only problem here is that there could be overlap in supported Glide level, but this should be solved by making sure to put V1 drivers in the folders with games that require them.
The system I want to build won't need a V3, so I should be able to eventually have it set up like this:
Matrox for 2D->Voodoo 1->Voodoo 2->Second Voodoo 2 for SLI->Monitor
Just gotta get my hands on a Matrox, V1, and second V2. For the bare basics of the setup, to test my theory out, I'll just need a V1 and I can use non-SLI V2 and any 2D card for now.