Hard disagree. "More discussions once more opinionated developers join" is universally true regardless of which frameworks/philosophies you start with. The point of convention being more important than configuration is that it reduces those conversations, because you can rely on the conventions as a default.
If an opinionated developer thinks a different configuration is better, then that helps form the conversation immediately. Everyone is already familiar with the convention, so the discussion only needs to inform everyone about the pros/cons of the alternative.
Sure, although English is absolutely the dominant language in almost all of the Republic of Ireland, where in Malta the situation is similar to the Netherlands, where most people it's just a very proficient second language.
I would recommend separation of those applications into respective sub-accounts. The hierarchy can be defined in AWS Organizations and you avoid resource overlapping of any kind.
All these applications use the same backend and what not. This makes it easier to share access / permissions vis security groups and IAM role. Its actually separated quite well, just rediculous that if I try to destroy an environment I can't.
However, convention over configuration means quicker delivery for small(er) teams, but more discussions once more opinionated developers join.