Guys, the various military tracked vehicles - battle tanks, armored personnel carriers, self propelled guns, etc. - place their power packs (that's the engine and transmission/final drive unit) according to a whole bunch of factors. Some of those factors are its center of gravity (on battle tanks the turret alone can weigh 21 tons or more, which means it HAS to be in the center of the vehicle, etc., etc.), the type activity the vehicle will engage in (SP guns need a lot of room in the crew compartment for the gun crew to serve the gun), and even protection for the bodies inside (most armored personnel carriers and infantry combat vehicles have the power pack in the front of the vehicle so anything hitting the front of the vehicle will have to penetrate a big ol' chunk of power pack in order to get to the grunts packed in the troop compartment).
The other item of note about track on military vehicles - especially Western European ones - is the difference between live and dead track. This dozer has dead track, it's just pinned together and flops around. That takes a lot of power to pick it up off the ground and bend it around the sprocket. Live track, on the other hand, is constructed using a rubber bushing around the track pins which causes each track shoe to want to bend inward. It WANTS to bend around the first and last road wheels, the sprocket, and the idler wheel. Although live track is heavier than dead track, it actually takes less power to move it off the ground and around the sprockets.
Sum of all the above? Don't even think of comparing military tracked vehicles' final drive placement and track type to dozers and crawler tractors. My M-1 never pushed dirt, and a D9 Cat never has to worry about taking a hit from a 125mm.
