How many Vortechs can I control with one module? It looks like just two according to the picture.

At one point I was controlling four Tunzes at one time and it seems to me that to do the same with 4 Vortechs I would have to spend another $300 ($150 per controller). Please tell me I am misunderstanding something and this is not the case. I was thinking about switching to the Vortechs but this is ridiculous. Can I put two MP40s on a splitter coming out of the PIII like I can my Tunzes? I want three MP40s in my tank but don't want to spend an extra $150 just to add one more pump. I looked and cant find the answer so I'm asking now.