RE: Wheel pants?
I have never had an issue with wheel pants and grass when they've been mounted securely.
For general mounting, I use 4mm bolts for axles. Bolt goes through landing gear and through hole in wheel pant, then through nut to hold the wheel pant on. Then the wheel (maybe a plastic spacer in there if necessary) and another nut. The most important part is that the bolt needs to come out the other side of the wheel pant.
So you have one bolt, two nuts, possibly some spacers and/or washers to keep things nice.
If the bolt doesn't go through both sides of the wheel pant, then grass can pull the wheel pant off to the side and crack it. Having the bolt go fully through gives it a ton of extra support.
You'll notice I don't generally use pins to hold the wheel pant from rotating. You can get the bolts tight enough, no problem. If the field is *that bad, the pant might rotate a little and you move it back. So the movement absorbs a lot of energy that could otherwise cause damage.