In an unexpected twist of fate, our two heroes meet.

As told by Anthony Sim of Horse on an Arrow himself:

"I met Hendrix on a recon mission back in '87. The Cubans had Hendrix captive after a failed mission 2 years prior. My team infiltrated the camp where he was located and found him lying on the ground asleep with a beard as long as his hair. We've been friends ever since!!!!"

It didn't happen exactly like that, but it's an accurate depiction.