Two-dimensional transition metal dichalcogenides (2D TMDs) could enable high performance in aggressively scaled devices. Our intrinsic TMD modeling suggests monolithic 3D architecture may achieve the desired currents and AC performance. However, the contact resistance (R_C) is a major limitation at these dimensions and our calibrated model points to metal-TMD tunnelling gap (TG) as a critical factor. We demonstrate how optimized metal selection could curtail TG and lower R_C. Additionally, we emphasize the significance of contact doping and design within 3D architecture framework.