The Greyhound is
very good on paper, but hamstrung by its timing.
The idea behind the revamped Greyhound is it's not a shock unit: it comes too late to fill an M20 or AAHT's role. It's meant to be a very efficient later game light vehicle.
Thing is, when you get to CP5 (in 1v1) you're getting near the medium tank phase and putting a 70ish fuel delay on that first medium tank could be fatal. Therefore, you tend to delay until after your first medium tank. And that point, you might as well wait 40 fuel for a second Sherman, which is tougher and more versatile.
The commander's fairly off-meta right now though and it can no longer fight the vehicles meant to counter it, so you might get away with tying it to tech.
Against infantry, maybe. However, it loses to a 222 head-on, which is half the price.
That's what it's for. It's a USF Luchs. It'll beat 222s with the .50 cal.