Just because Randy wears something on their site, doesn't mean he actually wears them any other time. From all appearances he is a Combat Sports International/Title gear guy who uses HCK clothing. The guy has his own casuals line through HCK... I think it's clear where his loyalty lies. He wears Rockstar Energy Drink T shirts and sponsor patches but apparently he mainly drinks water or Light Force greens. Randy will wear whatever the people that pay to fund his training and Team Quest's bills ask him to, he's a business man like anyone else. I'm not saying Viktory clothing sucks, I have no experience of their products, but what Randy is paid to endorse and what he chooses to use appear to be quite different.
If you want to get a new rashguard, get one from XFGear. I think it's pretty much agreed upon that they are making the best quality rashguards for grappling purposes available right now. It also doesn't suck they can customise it so you can get whatever you want and have a unique rashguard.