this is my take on a standard r/g aggro/ramp deck
the reckoners are nice to have in just because no one sees it coming and its nice to have the 3 red devo to help pay for mizzium overload
but by far the best thing of all imo is my #1Kalonian Hydras, #2 Nykthos, #3 Mistcutter Hydra

the Hydras in this deck are amazing i even have Glaring Spotlight in SB to make my K.H Unblockable/Hexproof and it also helps for those mirror matches bc of the Caryathid
but lemme know what u think
http://deckbox.org/sets/542926

So the "aggro/ramp" is a myth. It's either a ramp deck (being necessarily mid-range) or an aggro deck.

That being said, this looks like more of a mid-range deck based on the fact that you're trying to ramp into sizable hydras. So I would suggest trying to focus completely on that fact. So I could easily see you dropping Experiment One, Scavenging Ooze, and Boros Reckoner to focus more on this fact. Exp likely isn't going to do much and is more of an aggro card (which you're not playing). Scooge can be moved to the SB for specific matchups, but overall it doesn't fit what you're doing. Reckoner really just won't be reliable as you're going to be hard pressed to hit that third red mana source early.

To be honest, you're close enough to the R/G devotion builds that I would suggest using them as a springboard into your build... Xenagos and Garruk, Caller of Beasts are huge in terms of generating card advantage and furthering your plan. I would also suggest looking into Reverent Hunter, Clan Defiance, Rubblebelt Raiders, Arbor Colossus, and even Ruric Thar, the Unbowed as possible options. Simply put, you will be best served as a primarily green ramp deck with a splash of red to give you access to some added pieces.

I'm linking you to an R/G build I've been tinkering with for a while. It's not a perfect build by any means and, to be honest, I really haven't playtested it much, but all the fundamentals are there. Feel free to take or leave any components you like. You can see the deck here: http://deckbox.org/sets/474989.