You can replant the stargrass, but it can tolerate some heavy hacking, which is much quicker and easier than replanting.
Just a suggestion. If you're looking for something bright red colored, might I suggest rotala macrandra?
I was actually thinking didiplis diandra might work in place of the stargrass as well. Mayaca fluviatilis might look good there if you're looking for a more wild/natural look.