Are Sand Soldier tokens able to be targeted by Decree of Discord? How about Viktor Recruit tokens?

No to both. Decree of Discord only targets enemy Order (C) units, and neither Sand Soldier tokens nor Viktor Recruit tokens have a domain — tokens are domainless by default (Rule 185.3.b).

• Sand Soldier = 2 Might, domainless, Shurima tag (Rule 187.3)
• Recruit = 1 Might, domainless, Recruit tag (Rule 187.1)

So neither qualifies as an Order unit, and Decree of Discord can't choose them — no matter their Might total. (This also sidesteps the token-ceases-to-exist issue for non-board zones under Rule 186.1, since the targeting restriction fails first.)