For a pyramid bow, wider limbs can be helpful as otherwise the bending portions near the tip can be quite narrow. If bending portions of limbs end up being thicker than they are wide, then it's easy for them to twist when under tension.
You might also consider making the bow wider than you want it to end up to start with, and tillering from both the sides and belly as you get the wood bending. It's been my experience that sometimes as wood bends, regardless which species, it can warp a little and sent tips that were aligned when you laid the bow out off kilter a bit.
