When something in your house breaks, you generally need to go find a part to fix it.
You go to the store, you find the part, and then you figure out how to take the old, broken part off and put the new shiny one on.
Sometimes they fit perfectly like a glove, like they were designed for it. But most times they don’t, either what you have is too old and you are now trying to mesh it with something new or vice-versa.
Regardless, you push to make it work, because if you don’t, well, whatever that thing that is broken, you’re throwing out and going to buy and entirely new thing which you probably don’t want to do and is invariably going to cost you more time and effort in the meantime.
The same goes for your team, something breaks, someone leaves, you find a new part, you figure out the best way to mesh them in, if you don’t, they always seem like this “hanger on” that never quite jives with what you are doing and now all you’ve done is made the problem worst.
When something in your team breaks, figure out why it broken before throwing it out and starting over again, might be it just needs a TLC, might be it needs a bit more, like a whole new part.