The instant and flying elements are certainly perks but you are much more into bodies to cost ratios than the benefits of flying
Sazh himself can call up a vital land or Bird card, while Bartz can make your flock gang up on a particular enemy when he enters
Determining rarity on these older cards can be tricky, so be sure to do your research before passing off Lion's Eye Diamond as a common

Beast Whisperer Whenever you cast a creature spell, draw a card Elder Gargaroth Vigilance, reach, trample Whenever Elder Gargaroth attacks or blocks, choose one Create a 3/3 green Beast creature token You gain 3 life Draw a card Ohran Frostfang Attacking creatures you control have deathtouch Whenever a creature you control deals combat damage to a player, draw a card Regal Force When Regal Force enters the battlefield, draw a card for each green creature you control Runic Armasaur Whenever an opponent activates an ability of a creature or land that isnt a mana ability, you may draw a card Toski, Bearer of Secrets This spell cant be countered Indestructible Toski, Bearer of Secrets attacks each combat if able Whenever a creature you control deals combat damage to a player, draw a card Non-Budget Enchantment Decks If you are playing an enchantment-focused deck, these are nearly mandatory inclusions to ensure you green card draw strategy

Then it saw play all over Modern Dredge and sometimes even Vengevine decks
Rad counters give your proliferate spells new purpose, and there are tons of ways to take advantage of milling everyone