You could also use a Digitrax DS52. It's a "dual" stationary decoder for tortoise machines, but each output has enough oomph to power two tortoise motors. And that's per manufacturer, not just me pushing things. I have that one decoder running a dual crossover on my layout and it throws all four tortoises beautifully. You do end up doing basically the same thing, though, which is programming both of its decoder channels to the same address so that they'll both work with one command instead of separately. I also use several of them on other single crossovers where they do function on two separate addresses. I found it to be the most economical option when you have three or four turnouts that can be put into one or two addresses and are close enough together to reach the same control unit.