The Beverly product is listed as a 4X concentrate of liver, as far as I can tell, the Universal product is not (so there is potentially a lot less liver per tab). This could easily explain the difference.
I would not make the mistake of thinking liver is dog food. The liver is one of the first choice organs eaten by predators when they make a kill...they probably innately know something we don't...and the old-time strongmen and early bodybuilders loved their liver, even without double-blind placebo-controlled studies to back up their thinking.
Dogs who get liver as a "byproduct" probably do better than those that don't.