It looks to me as though each of those modules have 5 LEDs in series, so they shouldn't be described as common cathode!
I think that by calling them common cathode, you have complicated the circuit requirements.
Where did the description common cathode come from? It's not mentioned at all in the seller's description, as far as i can see.
I would imagine that each individual LED is in fact a 350mA 1W device, to make the complete module 5W .
Are they still quite dim at 75mA?