I'm using groff in my version of green Stompy, and it can put some incredible pressure on an opponent. Throw in Elephant Guide or Rancor and things will end very quickly. But I have more creatures in this deck that I can play and I'm willing to sacrifice on T2.
If you want to go more for devotion then you could at least sideboard Nylea's Disciple, maybe even play 1-2 in the mainboard as her lifegain can safe the day for you. If you're not to hot for the carddraw dhen Arbor Elf could be used instead of Llanowar Visionary as it allows you to untap a forest enchanted by Wild Growth.
Track Down could be replaced with Adventure Awaits or Winding Way. Same mana-costs but Adventure digs 5 cards deep (only for creatures) and Winding way still digs 4 cards while Track down "only" digs 3 cards deep. Advantage of Track Down is that you can shuffle specific cards that you don't want under your library while the other two shuffle all those under the library or even in your graveyard.