@Riot: Juggernauts and Healing, Design Question

Hey riot designers: one commonality I've noticed among most Juggernauts that is not included in their standard subclass description (slow, melee, low CC, high base damage and defense) is healing. Most Juggernauts seem to have some form of self-sustain.

Garen's passive Darius' Q Mundo's ult Udyr's spammable shield & lifesteal Illaoi's tentacle healing Nasus' passive Olaf's W Yorick's E Mordekaiser's passive, Q, and ult Volibear's passive Trundle's passive and Ult

The only champ listed as a Juggernaut on the champion subclass list that doesn't have sustain is Shyvana.

I'm wondering if this is an intentional choice, or if it just happened that way? And if it was an intentional choice, why is this an appropriate strength for the Juggernaut class? Not saying it isn't, just curious about the reasoning.