Hi Barque. Here's the sentence:
"my own hesitance to spot poor fits and wait too long has resulted in: My own productivity dropping because I was preoccupied with trying to force a fit where there was none".
He means to say that even if an employee didn't fit in well (wasn't suitable for a particular position), he would try to change things around in an effort to make that employee suit the role, instead of hiring someone else who was more suitable. He tried to force a fit to happen even in situations where it was not possible.
So the "fit" is a suitable employee, and when trying to force a fit means he doesn't want to fire that "unsuitable employee"
I had hard times trying to understand it because I'm not native English speaker.
Thanks both of you Barque & Florentia