Artillery pieces are to be on wheels and rely on a tow truck to get it to where it need to be deploy. Once deployed, mostly are sitting ducks target. Now it relies on soldiers to prevent enemy from getting into them and blew them up to bits.
The first innovation is to mount the gun onto a mobile chassis and that is when a tank was born - out of necessity and innovation. The next incarnation could be having the firepower on feet. This is how the Quad-Gun Mech concept came about. On feet, it added a further degree of elevation and also to allow positioning on rocky, rugged, angled terrain.
I'd like to think this design is the early beginning of a full fledged Mech suit. Akin to the Mech body on tracks. Crew protection is also an important factor to consider. However, all advancement has to start somewhere.
