No idea if this one's a bit too off-the-wall... but though I might as well put it out there!

Number grids are a pleasing alternative and your solution has a neatness to it. Unfortunately the nature of numbers allow you to group them is many ways. Another solution is 1 prime factor (3 97 199 237), 2 prime factors (55 69 231 289), 3 prime factors (18, 30, 66, 99) and multiples of 4 (4 36 64 100) ... or ... What about going for multiples of 6 (18 30 36 66)? Then the given group that contains 99 will absorb the leftovers (and 2 of your groups are unchanged).

@TheCount

That was a concern - numbers can have a lot in common and there is nearly always a way to link any group of then.

I'll have a play with it based on your suggestions.