The problem is that "pale malt" isn't made from any single kind of barley. It's all labeled "pale malt," but the base grain could be 2 row Klages, but I've seen other grains.
Muntons Light LME is made from "Selected English lager malt." My feeling is that there will be a subtle difference in flavor - Muntons should be a little crisper, maybe marginally lighter. . . but they'll basically be the same. Because there's no SINGLE pale malt grain though, I think it would be unfair to say CATEGORICALLY that Munton's Light is different from Pale Malt in any specific ways.