Not with the mounts.
I do have a half wave VHF antenna on a couple of different UTV's. The pipe roll cages don't provide very good ground planes, so I've used Laird 1/2 wave antennas for about 10 years now.
While they do not require a ground plane, they do work better with one. Mounting it off to one end of the vehicle is still going to result in some amount of pattern change, but likely you'll never notice. Just make sure the whip is in the clear, and not down below the body line.
The Lairds have worked well. I've hit tree branches on trails doing 40mph. There's a very slight bend on the end of the whip on one of them, but nothing to worry about.
Last year, I squeezed through a culver under a railroad right of way. I had about 4 inches of clearance over the roll cage, so that folded the base spring on the antenna back at a 90º angle. Out the other side, it popped right back up as good as new.
While I'm a big fan of Larsen antennas, I've used a couple of these Laird 1/2 waves and they've lasted quite a while.
