Sure. In the plot he could outrank Tahu. But that doesn't really change his role in the set much though.
In a set with 4 minifigs one would be a matoran, two would be toa, and one would be a villain. That's a perfectly normal ratio of moveable versus non-movable figures. I think kids would be just fine with that.
Okay sure, that's great for dwarves. But we're making a line about the Toa not dwarves. The Toa are our characters here, they are not dwarves. They will make up the bulk of our minifigures. I don't see us ever having a set that does not include at least 1 toa in it. This example you've posted simply would not happen.
Because its something to talk about. We're having fun, but if you find its such a waste of time then by all means kindly exit this topic and let us continue discussing this without you. You have no obligation to push your presence on us and the experience will not be hampered with you gone.