You have to first identify the percentage of developers that fall into the over-engineer class. If it’s 30%, then it’s possible 30% of your team will over-abstract, and if you make them a principal, they will over engineer most of the codebase. These are scary people, because at least the duck-tape ‘just get it done’ people write sloppy but simple code (always needs to be cleaned up, but this is a lower load cognitively than unraveling the mental models of the over-engineers). Both can test one’s patience.

To keep running with the analogy, the sloppy developers will just take a credit card and max it out. The over-engineers will do credit default swaps on mortgage backed securities and tie up the whole economy.