I ask because I've noticed with some high-dollar acquisitions a lot of times "engineer #50" makes his/her "F-You Money" on the acquisition, but having been "engineer #2" and "#4" and even "#1" (sadly, no big exits) I am skeptical that #50 took on much more risk or contributed more than, say, #200.
#50 is probably being hired for very specific skills and experience (to mitigate technical risk) that increases their opportunity cost considerably, and you aren't going to get an engineer with a track record of scaling operations like yours unless they get a decent salary and a shot at a significant upside.
For certain skillsets and track records, when a startup is having severe growing pains, it becomes a sellers' market.
The list is small, but there are some obvious choices, even now.
Tangentially, I _really_ lucked out. I had other options that were lead engineer, or engineer #2-4, but this was unequivocally the best choice. The work is more interesting here too.