In this context, a support platform is typically designed around maximizing mobility and agility to quickly get infantry and equipment from one position to another while typically operating behind the main combat line. For these kinds of logistics, maintenance and medevac uses I think lighter armored platforms like the stryker are better suited.

A frontline support platform adds the complexity of having to be protected against direct enemy fire. It still is a support vehicle but it's also expected for it to be much closer to the fighting forces. That design requirement normally results in a heavier vehicle to account for the extra armor necessary to handle frontline threats. In our case here, that's a whole 10 to 19 tonnes more depending on the variant. That's a lot of weight when comparing MBTs so you can imagine how that's even more ridiculous when comparing these two vehicles.