My guess would be pinout is standard but Dell bios requires a specific resistance of fan quite different from third party vendor, therefore fan header may fail to deliver the appropriate current to drive Thermaltake fan because the load is different.  Dell fan header in its bios programming is not user friendly unlikely third party motherboard makers.
I plan on buying a 120mm riing thermaltake 3pin fan for my optiplex 3010 mt. If the cable colors match, would it work?
Optiplex 3010 Fans