If you are a capitalist, you should be pro-acquisition (i.e. of smaller firms) and anti-merger (for larger firms), because mergers are a form of crony capitalism that leads to reduced product quality and market dysfunction.

    First, merging firms reduce the number of products they sell, with the effects materializing one year after the M&A and accelerating over the next several years.
   
    Second, merging firms tend to  drop and add products at the periphery of their joint product portfolio.
   
    Third, the net effect is an increase in the similarity among the products that firms offer following a merger or acquisition.

This finding has been consistently true since people have started measuring merger outcomes, "we find that each merger is associated with a quality decrease (increase) in markets where the merging firms had (had no) pre-merger competition with each other, and the quality change can have a U-shaped relationship with pre-merger competition intensity. Consumer gains/losses associated with quality changes, which we monetize, are substantial " – https://www.sciencedirect.com/science/article/abs/pii/S01677...

It is doubtful that merging two companies would have improved the EU's capability to compete with Chinese state operators. On the other hand, lowering the capital threshold to create a new entrant would definitely improve the EU's competitive position and capabilities, https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=cele...

Even acquisitions can be problematic for competition. They often seem to be done for the purpose of gaining/protecting market share, with the acquired product getting dropped soon after.

I think most capitalists aren't pro or anti acquisition, for the simple fact that they don't believe they have the right to tell two people (or two groups of people) that they aren't allowed to associate with each other.

But if you're more consequentialist, you might take it on a case-by-case basis.