A laminated tiller will be stronger than a solid tiller of similar profile.
The arch is often fabricated for functional (ergonomic reasons), as well as aesthetic considerations. Consider hand-height, length (arm extension & back position), & any obstructions.
At one time, I used a solid ash axe-handle, for my emergency
tiller. It was strong “enough”, but less comfortable in use than the original curved (laminated) tiller.