What are the hubs designed for?

An issue with radial laced wheels is whether or not the hubs have enough "meat" between the spoke holes and the edge of the hub flange to handle the load. Using a crossing pattern solves that problem because the spoke is pulling at an angle where there's more material between the spoke hole and the edge.

Another thing you might want to look at is the thickness of the hub flange. If it's a steel hub with relatively thin flanges it might be a good idea to use spoke washers to fill in the extra space at the elbows.