This looks insanely massive compared to modern tanks, but comparing dimensions it’s not so different from modern battle tanks. In meters (length, width, height) this tank is 7.4, 3.1, 3.9; that height is to the top of the turret, the dome behind the soldier. A Leopard 2 is 7.72 (hull, not including gun), 3.75, 2.48; an M1 Abrams is 7.93 (hull, not including gun), 3.66, 2.44. So the main dimensional difference is it’s a lot taller. I guess maybe how built out the hull is makes a difference; the Fiat 2000 had a crew of 10 where the modern tanks I listed have a crew of 4. Or maybe the pictured soldiers are tiny.
Early tanks were hella crowded, and often had many guns which later tank designs would regard as superfluous (typically those along the side and back). Modern tanks, while tight, are designed more ergonomically, and have fewer positions that need manned.
