Looks about right. What do you mean only on one side? The extra velcro seems to be in case the front-back velcros are too short. Those thinner velcros serve to prevent fore-aft movement. Your panniers are far back on the rack, so there's more chance of bouncing into the wheel. Move them forward if heel clearance allows. I was worried about contact with the wheel since I was mountain biking. That's why I used a strap (or two) to connect those D-rings one can see in your photo. That tightens things up and greatly reduces movement of the bottom corners of the bags. If you do this, make the connection only tight enough to prevent movement; you don't want much load on the D-rings since they're not designed for it.