More than half the time it is correct - until you figure out those things you are asking to focus on you won't know what really works. Going for ideal now just means when you get to those things you discover another thing you hadn't thought of in advance and so you are no better off.

Experienced developers in a domain can sometimes anticipate the issues, but experience only comes from failing.

The real answer is allowing some budget to fix things and then fixing them as you go along.