With other -webkit prefixes, if you have something like

transform: scale(2);
-webkit-transform: scale(0.5);

the one that is higher in the cascade order (which for properties in the same declaration is the one that appears later) wins.

But as far as I can tell, none of those other prefixes properties have a behavior difference like with line-clamp, where the prefixed version has a dependence on other properties that isn't there in the unprefixed version.