You have some high converted mana costs across your board, and you run 36 lands 2 mana rocks + land tax, which seems to be quite scarce mana sources.
Do you get mana screwed some times? Trouble dishing out you big guys?
What I suggest is that you consider some of the following cards to add, while cutting some of the more expensive things here and there. Plus I would definitely reccomend to run 1-2 more lands.
In my opinion I would most likely cut these cards: Reya Dawnbringer (player her in my Sisay deck and never really wanted to paly her, she is just so damn expensiv and her effect isnt really that great), Tajic, Blade of the Legion ( I do not think he does much in this deck, because you dudes are all pretty expensive so his ability will rarely trigger, + Assemble the Legion does not justify him a slot in your deck), Wing Shards (I don't think you will go much higher than storm 2 or 3, wich is in your case already quite mana draining, how about Condemn to tuck opposing commanders and reliable removing the source of trouble from the field), Boldwyr Intimidator (nice flavour but he probably won't do much because yur guys are already pretty big or are flying to get through the enemy).
Now some cards you also should consider, they might improve your deck strategy greatly.
Blind Obedience (the black symbol in the hybrid mana of the reminder text does not get in conflict with you color identity, plus it slows down the opponent and he has to wait a turn for his blockers to be active)Austere Command , Akroma's Vengeance , Wrath of God (why isn't this in, very nice flavour with you commander), Return to Dust , Karmic Guide , Anger to get more haste, Balefire Dragon ,Urabrask the Hidden even more hate, Chaos Warp (very important and good spell),Hall of the Bandit Lord also haste, Slayers' Stronghold buff land, Sunhome, Fortress of the Legion
That is my contribution, hope it may help you.
AEther Vial and Quicksilver Amulet would help a lot. It's a bit of a drop (another $35 USD), but worth it for a deck with such high Converted Mana cost. Also Gauntlet of Power (it's a two edged sword, careful) and Explorer's Scope would help with the mana. Also, what is the benefit of running Ajani Goldmane over Ajani, Caller of the Pride ? Personal question, I love Ajani...