Yes that's true, but I think the only time it is convenient to use AoE runes over grounshaker spell is when you are luring monsters before you get to the pull, because during that time, when you are running, some of the monsters are far away from you and you might miss most of them with the groundshaker spell or you might have to stop for a few seconds and receive damage if you want to wait for them to get closer to use the spell.