that is the determing factor.
i leave the old wood on and install 1/2 inch
4x8 insulation sheating such as r-max as often as possible.how that extra thickness works on in relativity to the window and door frames is my determing factor.a big mess and added expense
in tearing off the old wood. other times i built out the window and door frames with furring strips before capping to get the trim to stand proud of the siding