I mix & match a lot & it's always fun to see what (subjectively) works & what doesn't. HHX Studio Crashes are pretty thin and even thinner near the edges, so it'd be pretty dark & sloshy even if paired with a weighty cymbal for volume compensation. I'm using a 15" 70's A made in Canada over a Medium Sabian SR2 right that's quite sloshy and dark, but the 70's A top is still far heavier than an HHX Studio Crash. Anyway, if it doesn't work out you could sell it, potentially to me (very subtle hint LOL) & buy a top that better suits your needed weight for a top hat.
I’ve got several crash hats.
Zildjian 16 K Dark Crash on the bottom (it’s a thicker brighter cymbal than the norm) with a Paiste 16 Traditional Crash on top. Sometimes I will swap out the Paiste with a Zildjian 16 K Constantinople Crash ... an incredible Zildjian marriage.
Sabian 15 AA Medium on the bottom with a Paiste 15 Masters on the top ... my favorite hat set.
At times, I will put a 15 under the 16 for that extra bit of sizzle.