You never really even know if there is a chemistry fit.
But, the Rams have done pretty well overall on such signings.
I remember early on it was Floyd's signing was questioned. Well, he's playing well, getting QB pressures and sacks, and is worth the money.
None of us know the actual circumstances on Robinson's signing and then the Cardiovascular problem. But if there was an intent to hide something, or an intent to just take the money and run, there are mechanisms for clawing it back.
My guess is that he is going to upgrade our Dline almost immediately. Men that big and strong and athletic don't grow on trees. Plus, it allows the Rams to move SJD out to DE, which is what the plan was originally, giving the Rams more depth and fresh bodies to rotate in.