On a well designed hull and with access to good quality boards, I think there are benefits by a slightly wider spacing: with 5-6 mm strips and 16-18" spacing, the strips work like drafting board battens to ensure hydrodynamic perfection. The more molds you add the greater precision is needed in cutting and positioning the molds to not accidentally impose areas with discontinuous derivatives, that may be hard to correct by sanding afterwards.
I use 5 mm strips even if the resulting hull thickness is to be 3,5-4 mm (competitive surfskis), removing 1-1,5 mm with a handheld power planer before laminating – the thicker strips are easier to handle and work with through the stripping process.