You're completely missing the point about cons btw. He's talking about soviet players using oorah to flank the MG, which pios prevent by sighting for the MG.
Generally the allies outnumber the axis players with mainline infantry early on. So for a bit it's an Axis MG + pioneer fighting an engineer and a con (for example). If axis loses that engagement and has to retreat the MG, they're going to constantly be on the back foot after it because of the sheer imbalance of infantry. (pio + gren VS. con, con, engineer)
That's why Axis has to have an advantage in setting up the MG and spotting for it. Plus, as mentioned earlier, they've got 4 man squads that they's otherwise have to check for MGs with their face. And here's the thing about allies not having as much sight for their MGs: when you start getting fired at, you're too far into the arc to just run back out. Consider it a blessing if the Axis player only shoots at you from max range, you get to keep your unit on the field and plan a counterattack.