motorised jockey wheel on anything other than perfectly flat concrete is about as much use as an ashtray on a motorbike.
the tyres are not aggressive enough, and even if they were they have almost no ground clearance, added to that little or no nose weight and you ain't going nowhere fast.
the type that use the trailer wheels are much better as shown by Ty Korrigan are the way to go, but you may need to experiment with tyre types as some are better than others.if you require grip fit a more aggressive tyre pattern, fitting a twin jockey wheel is a great help to in stopping sinking in soft ground. it is possible to with a little back yard ingenuity have the whole thing operated by remote control,, even wireless.
I've even seen a set up with a seat and steering bars fitted so you can practically drive it like a trike.