If they fit use them. The Penguins have a bypass built-in that even bypasses the bio-wheel if needed. So an off-brand cartridge that leaves a little gap is still going to work.
Having owned both Marineland/Penguin and Aqueon hang-on-back filters, I would say no on trying to swap pads. They're both totally different sizes and wont fit properly. There is a reusable plastic frame assembly you can buy for Penguin's that allows you to use your own media.
Basically why I never recommend such HOBs. AquaClears are so much easier with their basic sponges.