Training Grounds combo in extended/legacy

Hello everyone, welcome to my first post on Planeswalkers Guide. Today, I am going to talk about an extremely effective and cheap combo deck that can (and probably should) be played in extended or legacy.

As many of you will already know, extended been shrunk to just twice of standard, so this is the time for many innovative deckbuilders to come out with new decks that previously wouldn't stand against the older decks. The deck I will be talking about today, was an idea I threw out to my playgroup, and after forming it, the deck performed excellently. So here is the decklist.

Creatures: 21
4x Birds of Paradise
4x Llanowar Elves
4x Joraga Treespeaker
3x Elvish Archdruid
2x Stoneforge Mystic
4x Wake Thrasher

Non-creature Spells: 17
2x Idyllic Tutor
3x Training Ground
2x Helix Pinnacle
4x Umbral Mantle
3x Broken Ambitions
3x Mana Leak

Lands: 22
2x Sunpetal Grove
1x Glacial Fortress
3x Flooded Grove
2x Mystic Gate
3x Misty Rainforest
2x Arid Mesa
4x Forest
3x Island
2x Plains

Basically, this deck's goal is to get out a mana dork, equip it with Umbral Mantle, have Training Grounds out, and pump it infinitely. Since Umbral Mantle gives the ability to the creature, the cost of 3 colorless mana, turns to just 1 ! If you equip it to a leveled Joraga Treespeaker, or an Elvish Archdruid with lots of elves on the battlefield, you basically get infinite mana (Which goes well with broken ambitions), and the untapping also pumps your Wake Thrasher. Not too shabby right ? Did I mention a possible 3rd turn kill ?

In Legacy, there's a possibility of a 2nd turn kill (well, except when your opponent has Force of Will...). Here's the decklist for Legacy Training Grounds combo (lol, can someone help me think of a better name ? )

Creatures: 21
4x Birds of Paradise
4x Llanowar Elves
4x Joraga Treespeaker
2x Elvish Archdruid
3x Stoneforge Mystic
4x Wake Thrasher

Non-creature Spells: 19
4x Chrome Mox
3x Force of Will
2x Broken Ambitions
2x Idyllic Tutor
3x Training Grounds
1x Helix Pinnacle
4x Umbral Mantle

Lands: 20
2x Savannah
2x Tundra
2x Tropical Island
4x Misty Rainforest
4x Flooded Strand
6x Forest

If you think the manabase is too expensive, it's fine to change it as it doesn't really affect the deck much.

If any of you have any great ideas for extended (or any format at all), please do share it with me ! I may even post it in the next post !