It's typical Sony stupidity. They just acquired the talent they had at Studio Liverpool again but paid for it. Watch they'll do it again for their Japanese studio. MS caught Sony off guard with the Zenimax purchase and now Sony is scrambling. If they had managed their teams far better Liverpool and Evolution would still be Sony.
This has zero to do with the Bethesda acquisition. It's not at all the same and it's not at all meant to be an attempt at achieving parity. You're just doing fan-math of chalking up 'acquisitions vs acquisitions' on a toteboard, but there is no comparison drawn or intended in reality. Sony's not scrambling with Firesprite and Nixxes and whatever, this is just something that happens at an inflection point for a company (say at the launch or early years of a platform, when new partners are made and some acquisitions line up) when they're looking at what's needed to help them reach their future plans.
Microsoft acquired a fucking publisher, with all of its brands and studios. You don't battle against a major (and, in gaming, fairly unprecedented) move like that with little chipper shots of a fraction of the caliber. Instead, you re-assess your forward-thinking strategy, you look at your competitive analysis to see what the rivals are doing to position themselves for their version of success, you adjust your future plans for what moves the competition has and may do down the line, you plan out strategic moves that work for your new gameplan (which may be a total rewrite after the megaton event your competition made, or it may be a reshaped version of the previous plan if you still feel it's right for your business and can adjust for the shift in the competitive landscape,) and you move forward. Only a good plan for your own particular business can work when the competition makes such waves in the market, not trying to go move-for-move with the rival when that's not your strength in or approach to the market. You might still get crushed, if the competition really does have that swole a warchest and its approach proves to be where the market flows, but you're sure to get your ass kicked if you try to bring a knife to a battleaxe fight.