I'm glad the article goes into STB. I really think this was what killed 3Dfx. It was a big move, but if you were following 3Dfx back the, you saw the issues.
I think they tried to lay off duplicate staff. With the Voodoo3, you saw drivers that just didn't work half the time. Textures were rendered totally wrong, people would downgrade drivers to get things working, etc. I have a felling they laid off or lost people critical in the hardware itself.
The website went to shit too. It got terrible. They either axed or lost a ton of web staff and focused more on the graphics used on all their box art.
Finally, the cards/chips just didn't scale well. I even remember a ton of articles at the time talking about how much efficiency was lost with the multi-chip design; how many things had to be duplicated in memory for the different GPUs. The Voodoo5 even required an external plugin power source.
nVidia to this day still sells its chips to everyone else. 3Dfx was trying to get into the ATi space, where you only had one ATi card and didn't have to worry about reference vs vendor drivers. It might have worked if they tried to keep both units separate for a while and not merge them into one entity.