Paladin Tree
Paladin tree is focus on Firepower & Team Survivability. Its a perfect class tree that for keeping your team uninjured and use AOE firepower to wipe out covers and a group of enemy. Cause every peaks in this tree perform perfect, maybe a lot OP, I suggest nerf some of them.

Renewal Protocol in Sergeant
When using Renewal Protocol to revive a teammate, he will be uncontrollable after revive. This bug happen everytime in my test. The second bug of Renewal is it can heal Spark. This bug seems like a feature for me. In legend, Spark take tons of time to repair before your Spark learn Repair peak in Captain. So, I suggest adding repair Spark in description.

Shields Up & Aegis in Captain/Major
Shields Up give 3 shield point to your teammates with Tire3 Gremlin. Aegis make damage reduction applies to all damage taken while shiled is up, not just damage absorbed by the shield. So, a teammates with Aegis Up take about 5 HP damage which get shoot by a Sectopod. One solution is make Aegis can`t combine with Shield Up. Another is move Aegis to Captain in Ghost Tree. Let player to choose between Aegis, Shield up & Sensor Overlays.
Stasis Field in Brigadier There are some discussion about nerf Stasis Field before. I consider it deserve a nerf. Stasis Field could save all of your teammates from incoming fire in one turn. And this peak could use every 4 turn. You could reuse Stasis Field to keep your team uninjured in a timeless mission. It should be a last chioce not conventional tactical. Therefore, one use per mission.

Ghost Tree
LightFoot and ECM in Corporal/Captain
Light Foot add 3 Mobility and make Dragoon 20% harder to detect while concealed. ECM make all teammates 20% harder to detect while concealed. ECM seems the worst peak in Captain to pickup. In my legend run, I can`t remember how many times my concealed soldier get detected by enemy. Maybe 4. So, ECM peak seems will not contribute to my team more than Shields Up and Sensor Overlays do. My suggestion is move Aegis to ECM, or buff ECM workable without concealed.

Tactical Sense in Major
Ghost Dragoon would always scout in concealed, Tactical Sense seems do not suit stealth style. How about put FirstStrike or ShadowStrike here?

Reverse Engineering & Puppet Protocol in Brigadier
Dragoon with Reverse Engineering, will get permanent 5 Hacking score after hacking, even hacking fail. Puppet Protocol takes permanent control a Sectopod in late game. Although both peak are great, Reverse Engineering should be reduce to 2~3 Hacking

Middle Tree
Advanced Shield Protocol and Supercharge in Sergeant/Brigadier
A Brigadier Dragoon get 2 charges Shield Protocol and 2 charges Renewal/Stealth Protocol with tier3 Gremlin. Therefore, Supercharge Dragoon get 3 Shield+Renewal or 3 Shield+Stealth with tier3 Gremlin. If you learn Advanced Shield Protocol before, you only get 3 Shield after you learn Supercharge. My suggestion is Advanced Shield Protocol should add 1 or 2 charges to Shield Protocol.

Iron Will & Damage Control
Seems Iron Will suit Combat Engineer more, because of Close Combat Specialist. Damage Control seems underpower in this rank, maybe change to somethings useful.