I've got a better idea.
The jungle enchantments and the other upgrades
aren't actives. Instead, they are additions to the Smite summoner spell. Which means they can have attached actives.
+
= Eye of the Skirmisher
+
= Eye of the Stalker
The combine can be done enchanted or unenchanted, and will carry the enchantment over.
Eye of the Skirmisher:
Special bonus experience on jungle monster kill
Unique Passive: Tooth/Nail
Unique Passive: Challenging Smite
Unique Active: Warding 4
Eye of the Stalker:
Special bonus experience on jungle monster kill
Unique Passive: Tooth/Nail
Unique Passive: Chilling Smite
Unique Active: Warding 4
And even bring back Ranger's Trailblazer, so we still have 3 choices.
Ranger's Trailblazer:
Special bonus experience on jungle monster kill
Unique Passive: Tooth/Nail
Unique Passive: Empowered Smite
Empowered Smite: Your Smite deals 20% (number subject to change) bonus damage.
Eye of the Ranger = Ranger's Trailblazer + Sightstone
Special bonus experience on jungle monster kill
Unique Passive: Tooth/Nail
Unique Passive: Empowered Smite
Unique Passive: Warding 4
The balance in giving Smite extra damage is that Smite can't be used on players still. It's stronger so you can outsmite enemy junglers on objectives, however you can't have it and Challenging/Chilling Smite both. Challenging Smite is much stronger in teamfights. Chilling Smite is much stronger for ganks. Empowered Smite is stronger for contesting objectives.