A question about CZM properties mismatching in joints such as weldments and their influence

Peace be upon you everybody;

In welding process of joining materials, and due to the highly localised heat imput, it is expected to find diffrent microstructures in the two sides of the weld line and even whithing the weldline,  as a consequence the mechanical properties (and in some dissimilar weldings the stiffness or elastic properties) of these diffrent zones are expected to be diffrent, this mismatching is widely studied in several articles, and since the cohesive zone models are caracterised by parameters related to the mechanical properties of the material and since the cohesive process zone's properties are  dependante of the mechanical parameters of the zone considered so these cohesive parameters are expected to be variable in diffrent zones of the weldment, so if we consider a traction-separation model we have the critical-cohesive stress (or -cohesive traction), the critical opening of the process zone and the critical cohesive-energy (necessary to create the new crack surface) and according to many works on the experimantal determination of the cohesive-critical-strength this one is cracterise by a significant mismatch across the weld line, and in the critical opening which is in the order of micrometers in metals and alloys:

here i have a question:

is it convenient to say that the mismatching in the critical-opening (which is expected to be on the order of micrometers in metals and alloys)  has a negligeable effect on the crack driving forces compaired to the mismatching in the critical-cohesive-strength?

 this assumption is very important in the modeling of fracture in welding joints if we consider the fact that both cohesive parameters impose diffrent difficulties in expertimental determination.