I think the show makes it quite clear he's the kind of guy extremely guilty people would call to be their lawyer. Most of them don't really care for trial, they're just looking for a nice plea bargain to get off. Some of them don't even understand the stakes, as depicted. The two crackheads make a sequence about that.
I mean most of his cases are quite obvious prosecution slamdunks and they'll get worse with discovery / trial procedure. The ADA / Saul elevator scene is just there for Saul to get some time he'd normally doesn't have because he's a billboard lawyer 99% of ADAs wouldn't care since they have 90h / week workload in normal times.
The Mexican storyline is getting quite genuine, where it's easier to "move" product than cash. Moving product is simple logistics, moving cash is hard since it takes a lot more space than drugs, and distribution / control requires a lot of manpower and management. I think Gus is at that point where cash management would be easier with less people getting their beak in.