I figured it allllllll out.
I learned in Beverly Hills Cop 2 that Carlos in Spanish means Charles. And a shorter name for Charles is Chuck.
Saul's brother Chuck, is really a half brother, of Chilean decent, under the alias of Carlos Boozer, as mentioned on the previous page.
And Mike, was in Beverly Hills Cop 1.
Carlos Boozer now resides, in Beverly Hills.
So Carlos, is really Chuck, and is related to Gus, which is how Saul comes to meet with Gus, when Carlos/Chuck meets with Mike in Beverly Hills and vouches for him.
Eddie Murphy foreshadowed these events in the mid 80's, but we weren't ready for it.
"Chinge sun puerco signed Carlos"