In my experience, when that happens it's most likely because you drew the wrong boundaries. Iterating on the boundaries also becomes quite cheap when developing this way though, you should never expect to get them right the first time unless it's a very common problem you're solving _or_ you've done it before.

> path of excessive modularity with each module being excessively complex

its contradicting metrics. You either have modules being excessively complex and not enough modularity or vice versa