That's a pretty gross oversimplification of the changes made, but if we engage with it on that level: Why shouldn't an army with literally twice the amount of soldiers be better? Strongly imbalanced battles like this usually did end overwhelmingly in favour of the numerically superior foe, unless the smaller side had some kind of force multiplier, or an advantage EU4 cannot currently simulate, such as trouble relaying accurate orders to the whole army due to linguistical differences.
An argument could be made (and I'm tempted to make it) in favour of a "max command capacity", similar to the Combined Arms where your cav gets worse if you exceed the ratio, but for army stacks. I.e. you get penalties for engaging with an army over X size, simulating command chain complications. X could be increased from tech, better generals, ideas and policies (a Quality-Quantity policy comes to mind...), but that's outside the scope of the discussion.
I haven't played as much with the current patch as I'd like, but from what I've played, I like the changes. Troop quality, while it still gives an edge, doesn't as quickly make you space marines capable of stackwiping larger armies than your own while marching across rivers. It's too early for me to say whether I prefer it over the old system or not, and it's going to take some getting used to, but rolling back a change without giving it a chance to settle because we're used to the old meta isn't the right thing to do.
