To be honest, getting expertise capped is stupidly easy as a paladin, as compared to the other 3 tanks.
-3/3 Combat Expertise gives you 6 Expertise.
-The Glyph of Vengeance gives a disgusting 10 expertise.
That's 16 out of 26 with no effort, leaving you fill in only 10.
And, if you are an orc, dwarf or human, you have even less of an excuse,
-5 expertise from axes for orcs (falric wrist chopper from H HoR, last laugh from N25 KT),
-5 for maces if a Dwarf (Lucky Old Sun from reg FoS, a few from ulduar 10 man),
-3 expertise for swords OR maces if human (if you can't find a tanking mace or sword, stop tanking right now).
If you are one of those beloved races, that's 5 expertise skill to obtain if orc or dwarf, or 7 if a human.
Bears get 10 expertise from primal precision. No racial bonuses, obviously.
Warriors get 6 expertise from Vitality. Racials apply.
DKs get 5 expertise (6 if blood) from talents. Racials apply
I don't see why not orc paladins, they are just as noble as the Taurens freed from the Legion's influence.
Back to the post at hand..
Orc DKs/Warriors still get 5 expertise if they can find a good axe, I haven't looked to see what the best tank weapon is considering all wings of ICC including heroic modes. Would have been nice if they kept horde specific drops as well as alliance ones, like they did for ToC. Didn't make sense in ToC but it would in ICC.
due to the flavor text on the LK 25 heroic tanking mace..... being horde......
unless the 2.0 speed on heroic Troggbane is a typo it'll be my BiS choice
orc racial + tank stats + average speed= win
more mathy way of looking at it would be:
heroic Troggbane vs heroic Mithrios
Mithrios has 2 more stam
Troggbane has 2 more strength
Mithrios has 20 more def rating
Troggbane has 32 parry
Mithrios has 9 more dodge
Mithrios has .12 more expertise(factoring in orc racial)
Troggbane doesn't say "FOR THE ALLIANCE AND FOR KHAZ MODAN"
if we compare them at the same iLvl(heroic Troggbane VS Mithrios)
Troggbane has a blue socket + socket bonus that Mithrios doesn't
Troggbane has 10 more strength
Mithrios has 13 more defense rating
Troggbane has 32 dodge rating
Mithrios has 10 more parry rating
Troggbane has .36 more expertise (with orc racial)
niether has bad faction specific flavor text
and seeing as at the moment i have alot more chance of downing Heroic LK 10 man than even regular 25 man Troggbane is the clear choice for me, though you may have different circumstances