Theres a common theme on bike touring sites with a reason.
Ortlieb panniers and Tubus racks.
Might there be other stuff out there that works?
Sure.... I guess.

I've given up trying to save a dollar by buying second rate gear that ends up failing when I need it most.

My gear includes Front and Rear Ortlieb Roller Classics and bar bag Ortlieb Ultimate 6 (I think) and Tubus Cosmo and Nova stainless racks that neither rust (hopefully) nor have paint to scratch.

This gear lasts and does what its supposed to whilst keeping my stuff dry in any conditions.

Good luck with your purchase decision.