If he's naturally switching between his hides intermittently, and isn't showing exclusive preference for one hide, I think you're probably fine. The "two identical hides" point is helpful if you're troubleshooting why a BP might be behaving abnormally, but it's not an absolute must if your BP is doing just fine. My boy has two different hides - a plastic hollow tree stump on the warm side, and a Zilla rock lair on the cool side - and he uses both as he pleases.