Is there a way to differentiate between sand bass/hybrids and largemouth bass on traditional sonar?

yes, that's pretty easy - sandies will usually be in a large school where fish will be distinguishable, like a ball of shad only the individual "spots" that make up the ball will be larger and more distinguished. Bass will usually be more spread out and individual and create and arch on your sonar. Just takes time on the water and reading graphs to get it, but once you see a big school of sandies, you know what they look like. go to the sandbass section and look at graph pics of sandies.

^^^yep, what Frank said

Now, spotted bass and very young northern strain LMB behave very similar to sand bass/hybrids. They like to school and chase, expending a lot of energy running down smaller bait

Florida strain LMB are fat, lazy loners that seek an ambush spot where they can have a buffet by themselves or just a few others. They spend the least amount of energy for the most calories.