got to make clear, broadcom-wl or broadcom-wl-dkms is technically the same driver. only DKMS is you use a kernel like linux-zen and linux-lts you need also a module of those. thats why you need the DKMS driver and the headers of those kernels to compile a module, broadcom-wl is a module for the ‘linux’ kernel. but since some kernel modules is loaded, probably some conflict. since broadcom-wl was already there , i would say is a conflict…
is just i want to enlighted it… since you use linux kernel. 