Paladin tanking spells are all instant cast, so I would suggest using /castsequence rather than /castrandom. This allows you to tune so that your spells occur in exactly the order you want.

Personally, I use a very long 6969 macro that exceeds the standard character limit (thanks macaroon), but it could very easily be replaced with /click sequences such as below. This leads off with HotR, my preference, as I usually prioritize multi target threat first. This would result in the following cast sequence.

HotR, HS, SoR, Cons, HotR, JoW, SoR, HS, HotR, Cons, SoR, JoW repeat

Button 3 would cause random Exorcisms, HoW & AS throws when they were up and not blocked by a GCD... My first impulse wsa to remove this section, but I may switch to this myself, as they are unlikely to fire much when button 2 and button 3 are firing... but could fire alot in situations where your not near your target (the dance on Heigan for example...)

Code:
// Assuming 6 clicks per second

// BUTTON1
/click BUTTON2
/click BUTTON3
/click BUTTON4

// BUTTON2
/castsequence reset=combat Hammer of the Righteous ,,,,,, ,,, Shield of Righteousness ,,, ,,,,,,
// BUTTON3
/castsequence reset=combat Holy Shield ,,,,,, ,,,,,, ,,,,,, Consecration ,,,,,, ,,,,,, ,,,,,,  Judgement of Wisdom ,,,,,, ,,,,,,
// BUTTON4
/castrandom Exorcism, Hammer of Wrath, Avenger's Shield