>>58832982large plushies can get very intrusive and take up bed space, so it's pretty subjective what size you prefer. It's usually collectors of hard toys like statues and action figures who would care about size as they look better as decorative displays. However, some people might say a plushie is too small if its price point is too high.
It's hard to say what to expect from your Mimikyu since I'm not sure if they're measuring to ear tip? Here's how big my 8½ inch plushes are