Fat booties

I haven't seen one of these in a while. A few things that could be shifted around a bit to maybe help the build.

Running 19 lands in this build is almost certainly not feasible, especially when one of them is colorless, 4 of them enter tapped, and 2 others are either colorless or enter tapped (the fetch lands). You're going to be eating mulligans for days, and playing out hands when you get stuck on 2 mana and 2 colors, unable to cast your 3-drops and third color. I know you want to rely on Guardian and Caretaker to round out the mana and colors, but both are super conditional and slow. Guardian needs 3 mana and a turn to become available, and Caretaker needs another fielded critter, so you'll need your second land down and then probably won't be able to tap out for advantage turn 2 (when you put down the second land and critter) because you're stuck with Caretaker putting out only 1 mana. The good news is, this is pretty easy to solve in a way that won't hurt too much.

I wholeheartedly advocate for adding your 4 Overgrown Battlements over 2 Guardians and 2 other cards. They're guaranteed to tap for G, but will most likely net you at least GG, and will help the build snowball because of the synergy of letting you play more critters quickly which lets you add more mana, rinse and repeat. Combined with the draw abilities of other defender dudes and your topdeck casting and Battlements will become a mana fountain. I'd also advise upping the land count to 21 and cutting out Access Tunnel, as you REALLY need to hit your land drops turns 1-3, or this deck goes nowhere quickly. It also wouldn't hurt to cut down on the 3-drops in favor of more 1 and 2-drops. Ghostaway is a pain to hold onto, as you'll hamstring yourself by waiting to be able to cast it which won't let you cast anything else for many turns till you build up to at least 5 (more like 6) lands in play. Drift of Phantasms lets you fetch one of your combo pieces, but it eats a turn doing it (at sorcery speed), then you burn another turn fielding the combo piece, so I don't like the full 4 copies when you could be running Wall of Omens that speeds things up, replaces itself, and synergizes with everything.

Brave the Sands just isn't worth it. You won't need to block and attack in the same cycle because you'll be overwhelming opponent with damage they can't mitigate. Same idea with Skeleton Key. The draw/discard is nice, but the high equip cost is a major pain that'll stop your development cold for a turn, so you're better off with something more cost effective.

Another thing you could consider if you've got the money is Green Sun's Zenith, as it fits into this deck perfectly. You get to run the old Dryad Arbor trick, where you Zenith turn 1 for just G, fetch the Arbor, and effectively just got a land accelerant with a double deck thing (land pulled out, Zenith back in). Zenith also fetches your important pieces (Arcades, Wall of Blossoms for the refill if you need it, Overgrown Battlement if you need the mana). It's basically never a dead draw and does exactly what this deck wants, plus it combos with Battlement like a dream (more mana = faster search + even more mana the next turn). It costs close to 20 bucks a pop though, and Arbor goes for 2 bucks, so you're looking at an investment if you want to go that way. I very much think it would be worth it if you've got the money, but it is what it is.

Just some thoughts.