The Riflemen buff made Riflemen win harder at ranges they already won at.
If you fight them at range (which OST is very equipped to do) they're not any stronger.
But I totally disagree with such arguments
Now they will melt them more quickly, which gives you less reaction time and will mean that before grens retreat they will deal less damage. Also now rifles scale much differently against assault grens - they are much less vulnerable to ass grens. They will also melt support units more quickly. They will more easily wipe low health squads on retreat. Such things add up throughout the game. So they did get buffed. And all this without any buffs to grens, for example. I can completely understand ostheer claims for some buffs for tanks, for example.