I dont know what off-hand i should build so i want to know What is better Winter mitts (green) / lunar scimitar (gold).
Lunar Scimitar at gold is hands down better than Winter Mitts at green. It's actually also better than Winter Mitts at blue for ranged. The Army and Infantry Defense does not compensate the lack of attack and health.
You can count the stats yourself. If you're not attacking with range obviously you will want to use something else. When attacking you typically use 1 or 2 troop types. When defending you use all 3 troop types. What is best is situational.