Harmonize is a very interesting ability that allows you to tap a creature that you control to reduce the mana cost by an amount equal to its power, which means that it shouldnt be too difficult to tutor a big creature for just four green mana
Glare doesn't care if you're tapping a 1/1 Saproling, a 2/2 Wolf or a 12/12 Eldrazi, it just knows that the more creatures you tap, the more stuff of theirs you can tap, too
Making a second mouse with Offspring is obviously useful here, and if you've got loads of combat tricks, you could use one on the original creature, then one on its babby to give your entire mouse army a two-power buff
The bad thing is that your deck is very reliant on having a critical mass of artifacts to function
This enchantment is a fine top-end for just about any Green deck looking to take advantage of the political aspect of multiplayer by encouraging your opponents to attack each other instead of you