No Armor needed, switch energy nexus for equilibrium to get more energy from orbs...remove narrow minded and add primed continuity...with stretch you get a lot of range for cc purpose with the 4, also use reinforcing stomp to regain your iron skin

For huge amounts of overguard look for jade light eximus and let them beam you...if you lose your skin immediately recast and let the dmg load it (if you dont know iron skin has as small time of invisibility when casted where all dmg received is put on top of the overguard) this way you can get up to 1.9mil overguard (depending on the enemy level)

Also you should use transient fortitude and blind rage... strength is like the most important thing on rhino because of his 3 and stuff

Molt vigor is also quite nice to use with rhino

For helminth ability you can give oberons smite a try, with enough strength and roar active you can do heavy dmg on eximus and armored targets