There are many alternative cards can be perfectly mainboarded if that's your personal preference. Here's a handful of them:
-
Mangara of Corondor and Faceless Butcher fulfill the same role as cards like Fiend Hunter , Ravenous Chupacabra and Shriekmaw. They can be played if you think you need more spot removal.
-
Kheru Bloodsucker his triggered ability is free and will trigger a lot since most creatures in the deck have a high toughness. You could build around a bit more to assure the ability triggers, but it's pretty much done, since I picked high toughness cards over weaker ones so that Ayli's first ability works efficiently.
-
Angel of Despair fulfills the same role as Ashen Rider or Archon of Justice, though it's less efficient. The reason it is not inside the main deck is because it's the worse of those three and the slots are tight.
-
Angelic Chorus fulfills the same role as Proper Burial, Boon Reflection and Rhox Faithmender. I haven't find it necessary yet, since I've had no problem at all making it to 80-100-150 life total (depending on the match). Same goes for Alhammarret's Archive.
-
Corpse Dance should work very well because of it's buyback ability, though if I'm gonna pay 5 mana to reanimate something I'd prefer that creature to stay on the battlefield until I decide when to sacc it again.
-
Obzedat's Aid reanimates a permanent, it could be pretty useful if your playgroup are destroying your enchantments or artifacts too aften. Also Refurbish and Profound Journey might work.
-
Animate Dead yeah, this should be inside the deck. Why isn't it yet?
-
Endless Obedience is another good one-shot reanimation card that can mess with opponent's graveyards if prefered.
-
Emeria Angel should help if your playgroup is flying heavy. Entreat the Angels should go to maindeck too if that's your case. Fallen Angel could work too against those decks, it's also a sacc outlet utility card.
-
Luminate Primordial is clearly welcome. It comes in and out of my deck. The "for each opponent" part is amazing, but I don't like making them gain a bunch of life; i like to drain them, not feed them.
-
Wurmcoil Engine might be useful since it's like a all-in-one promotion lifegain, destruction, big-monster, token generator with more destruction and lifegain.
-
Faith's Fetters is the only "spot removal spell" i'd consider, since it can be very annoying for an opponent to have it's commander trapped in a pacifism. This one actually target permanents (so, it's pretty versatile) and it also has lifegain.
-
Marshal's Anthem might work. Haven't tested it yet.
-
Homeward Path should be inside if your playgroup likes to steal permanents.
-
Changeling Hero works fine in the deck. It activates ETB and LTB abilities of championed creatures, it has lifelink, it's an angel, it's a cleric, it's a dragon, it's a girl and a boy.
-
Dictate of Erebos , gravepact , Butcher of Malakir and Martyr's Bond are all good. You know what's good too? Friends are, and you'll lose them all if you play those cards in a deck like this.
-
Kor Haven is amazing, if you can/are willing to afford it, get it.
-
Linvala, Keeper of Silence can be amazing or not, depending on your playgroup. Be careful if you play her against opponents who can somehow gain control of your creatures, she's Ayli's nemesis.
-
Adarkar Valkyrie might be a bit slow without an instant impact on the battlefield, but can turn into a nightmare. Not to mention if combined with Illusionist's Bracers.
-
Dawnbreak Reclaimer and Benevolent Offering are both cards I love and actually play in this deck within my playgroup because we really enjoy the politics of commander. They are not the best in the world, but they are pretty good in the deck and SUPER fun.
-
Sheoldred, the Whispering One is a long-term value bomb, though it's a bit slow, if not taken care of quickly, might be a bit of a trouble. Another reanimator creature is Reya Dawnbringer which is the angelic creature version of Debtors' Knell. For the cost of 9 mana I'd rather play Rise of the Dark Realms instead.
-
Luminous Angel seems pretty slow and fragile for it's expensive mana cost. Haven't tried it though.
-
Helm of Possession could be amazing or terrible depending on your playgroup friends decks.
-
Mimic Vat is another one that should be part of the main deck, feel free to add it, I know I should.
-
Speaking of Mimic Vat , Phyrexian Processor and Nim Deathmantle ...those are cards that could use some Anointed Procession , right?
-
Angelic Renewal , Supernatural Stamina , Graceful Reprieve and even Cloudshift are all good cards that enables you either to make use of them at the very beggining doubling the benefits of your Solemn Simulacrum or to deliver a deadly strike while double ressing your Gray Merchant of Asphodel .
-
Oreskos Explorer , Pilgrim's Eye fulfill the same role as Knight of the White Orchid. It might be wise to cut a pair of ramp artifacts to put one or more of these inside the main deck.
-
Pearl Medallion is a card I like very much, but it's only useful in a deck that plays many spells per turn; otherwise, if you'll only be playing one spell per turn you'll be ok with an Orzhov Signet. This deck doesn't play many spells per turn. What it does, though, is consuming lots of mana on abilities. Unluckily, abilities are not affected by Pearl Medallion effect.
-
Speaking of ramp, sometimes Black Market performs amazingly well and sometimes it doesn't. Good option though.
-
Thran Dynamo could also earn it's place there, maybe replacing... I dunno.
-
Phyrexian Tower is kinda way far away from the this-is-as-far-as-i-go-for-a-non-competitive-deck budget zone, but HEY if you're up to, go ahead, it's an amazing land for this kind of deck!
-
Rune-Tail, Kitsune Ascendant
might help if you need to boost the power level of the deck to match your playgroup's.