The second ability costs 2BG (2 colorless, 1 Black, 1 Green). You sacrifice a nontoken creature (important that you can’t use a token) and you put X 1/1 green Saproling creature tokens onto the battlefield, where X is the sacrificed creature’s toughness. This is a pretty decent ability that can be used offensively and defensively. You could sacrifice a creature that will be destroyed by removal anyway, essentially negating that removal and getting Saproling tokens to replace it. It’s an even better ability in Commander where there are some creatures with massive amounts of toughness (Ghoultree, Tree of Redemption, etc.) which you can sacrifice for tons of token shenanigans.
He’s also an Elf, so for fans of green/black Elves, he can be fairly useful, especially since his second ability is even more powerful with how strong Elves can become over the course of a game!
The second ability costs 4G (4 colorless, 1 Green) and allows you to put a +1/+1 counters on target creature. There are plenty of far better ways, today at least, that can put these counters on creatures at a far lesser cost.
He is also an Elf Shaman, like his newer counterpart, but the abilities are clearly less powerful than the Korozda version. In Commander, I could see both working together. But he is clearly the weaker of the two here, and the disparity between the two cards’ power levels is not even really close .
Winner: Korozda Guildmage, by a good degree!