Monstrous Commanders

[Xantige]

I sat down to work out some stats for some Tyranid Warrior Models I have, and I thought I'd make my army's commander a Modified Warrior Model as well. However, it just didn't work. I classed the regular Warriors as Medium Mechas, which gave them a high soak, damage, etc. Meanwhile, my Warrior Commander was far weaker all around, but still the same size, thus, she was a bigger, softer target to hit than her "Mecha" sisters.

So, I was wondering if there was some way to do this, and if not, couldn't we see it in a future rules update? I can't be the only one wanting to field a large monster or robot to lead their army...