For 5 points and a command slot this upgrade adds the Guardian 1 keyword to every unit at range one of the unit that has this upgrade only while the unit that has this upgrade is defending against an attack.
At 5 points Esteemed Leader is fairly inexpensive for a command slot upgrade, especially if you take into account that this will save wounds on your unit allowing them to use more of their abilities and command cards later into the game. The more corps troop units you surround your commander with, the more valuable this upgrade becomes.
Esteemed Leader is a great upgrade for the less durable commanders such as Veers and Leia, ensuring they last longer into the game and are able to fully use their abilities. It is also a great psychological deterrent - even if you would only be able to prevent 1 wound using Esteemed Leader's Guardian ability often opponents will skip the attack altogether targeting a different unit when in actuality they could likely push a moderate amount of damage through onto your leader.
General Veers Expansion, Leia Organa Expansion