Your deck seems to have a few mixed themes... at first it seems like an Elf deck, and if that's what you want then I would go and make every creature an Elf, except maybe one or two utility creatures (eg
Acidic Slime,
Thragtusk,
Cloudthresher, something like that).
If it's more of a ramp deck, then
forget the Elf lords (except
Elvish Archdruid, the best and cheapest one... where is it??) and
concentrate on trying to ramp into something backbreaking. Also take out the Overruns if you're trying to play a few big creatures rather than a swarm of little ones.
You should be able to do better at the 6-slot, even on a budget. The aforementioned
Cloudthresher is great because it has
flash and can be paid for its evoke costs if needed to take out small flyers.
Essence of the Wild could be good because it turns all other mana dorks you might play afterwards into 6/6s.
Soul of the Harvest can also make your mana dorks good in the late game because each time you play one you then draw a card. It works whether or not you have cast the creature, so token makers would go really well with it (eg.
Sprout Swarm).
Steel Hellkite could blow up their stuff.
Not at 6 mana but still mana intensive, Polukranos could do good work because you can use it to kill your opponent's creatures.
Wolfbriar Elemental is also great because you can cast it for 4, 5, 6, etc mana and it just gets better and better. It's also way harder to deal with a bunch of little creatures than one single big one unless the big one has some kind of evasion (usually Trample with green).
If you can splash red Ruric Thar could be great as it would shut down any non-creature spell heavy deck.
Hopefully these are helpful ideas.