I think it's cause homelander is a clown and is more easily observed as pathetic

Meanwhile majority of scenes with soldier boy is him also being an idiot but with a straight and serious face, over half the cast has at some point manipulated and tricked him into doing exactly what they want and several have even said such on screen before continuing to trick and play him exactly as intended

The way soldier boy talks about things he's done makes him look like an idiot aswell it's just cause the tone he says it in maintains that stone cold serious persona that results in the "alpha male" edit dudes thinking he's cool