I have never found this argument in favor of Catholicism to be very persuasive. Frankly, the criticism of the argument is correct - Christianity and even Catholicism are not markedly more uniform in belief or practice than other faiths. Even if you look only at the Catholic faith, the Church is itself fairly broad, with a lot of room for varying interpretations even within Catholicism. Just go to any thread on this forum about biblical interpretation, or justification, and you can see how diverse opinions are within the Church.
More importantly, I don’t see how homogeneity is a good proxy for correctness. Lots of movements with very strong centrally controlled belief systems turn out to be very wrong. The strength of the Church is in its universal nature - hence the name - and that very nature leads to differences in belief and practice. That diversity is a strength, not a weakness.