can you clarify to me, why there is no WID in AXI4?
WID is needed to support write data interleaving described in AXI3, but this isn't supported in AXI4, so no requirement to have a WID signal.
See section A5.4.1 in the current AXI protocol spec for details of this.
And as section A5.4.2 states, if you have an AXI3 legacy deisgn which needs a WID input, this can be generated using the ID conveyed on AWID.