No. Its not that simple. Its more like 1 + 1 = 2.5 in that - as a rule - hybrids are often capable of tolerating conditions that exceed the extremes of either parent, even when both are highland types, for example. Its as if by crossing two distinct species you end up expanding the capacity of both species to adapt to conditions that diverge from the norm for either. I'm speaking in generalities, of course; there are always exceptions.