The Even Keel and The Accelerator
These are general tendencies, not rules or predictions. People are more than their structure.
How they meet
The Accelerator feels switched on in a crisis and decides fast. The Even Keel does not feel the need to move just because the ground did.
What tends to work
The Accelerator gets things started that would otherwise wait too long. The Even Keel is a good test for a fast idea: if it still makes sense when said calmly, it is probably sound. Neither of you needs drama to respect the other.
Where it strains
The Accelerator can read The Even Keel's calm as not caring about the outcome. The Even Keel can read The Accelerator's urgency as creating problems to solve. Quiet periods suit one of you and unsettle the other.
What helps
Separate "this is urgent" from "I want to move." The Accelerator can say which one it is. The Even Keel can give a clear yes or no quickly, since waiting is what The Accelerator finds hardest.