In my experience, if the move "benefits the company" and the overall company governance is not dysfunctional, then the leader responsible does not get hurt by it. At least not in the long term.
Mergers are always risky. CEO can do all the analysis possible but can't know for sure if combined company will do better or worse than individual parts. That part of the job is called "taking calculated risks".
True, but growth-by-acquisition is a lot "easier" than organic (R&D-driven) growth, particularly when money is cheap.
A CEO looking for a quick win - usually quarterly, sometimes annually - will almost always default to an acquisition. It won't be clear for at least 2-3 years whether or not it was worthwhile.
I think a CEO who spurns acquisitions in favour of organic R&D will always, almost by definition, be putting the company's interests ahead of his/her own.
My experience in large enterprises are that there are two kinds of "politics" that get played.
In one form, the leadership makes moves or take actions that benefit themselves but also help the company. Often that is called out as "leadership."
In the other form, the leadership makes moves or take actions that benefit themselves but hurts the company. That form is called "politics."
You can see examples all around of this. For example a CEO that buys another company, the result of which is hitting a milestone that triggers a big bonus for them but saddles the company with a bunch of debt and expense that drags down its productivity. That is bad. Versus the same example where the CEO buys another company and the combination results both in them getting a bonus as well as the combined company doing better than the sum of the individual companies. That is good.
So I agree with you that both parties are playing games, the differentiator for me is what is the ratio of benefit to the country vs benefit to the party/individual from the game being played? If that ration is 1:1 or greater I see it as a positive thing rather than a negative thing.