Aahh, no, TC will also slow them down as well. If it senses a wheel slipping, it will brake that wheel, which slows the 4wd down, and on sand , momentum is what you want.
TC will work good on dirt and rocky ground where there is traction to be had, but not on sand.
Personally I don't have TC on mine but there has been much discussion and sharing of experiences about this topic on the Pajero Club forum.
Basically TC will help prevent wheel spin across axles by braking the wheel ON THAT AXLE that is spinning fastest, leaving the other axle alone.
ASC will attempt to prevent wheel spin across all 4 wheels by braking both wheels on the opposite side of the vehicle in an attempt to prevent the vehicle from slewing dangerously at highway speed. The many youtube videos of lane change tests clearly demonstrate this.
Anecdotal evidence on the Paj forum indicates that TC has no ill effects in soft sand, whereas ASC will kill momentum very quickly. In the Paj you can't turn off the TC, only the ASC, and they tow fine on soft sand, as long as ASC is disabled.