I want to express the same meaning with the following noun phrases:
1. combat troops.
2. fighting troops.
3. a fight troop.
4. troops for fighting.
5. armed troops.
Question:
Which is/are grammatically correct ?
Correct them please if they are wrongly written.

Question

I want to express the same meaning with the following noun phrases:
1. combat troops.
2. fighting troops.
3. a fight troop.
4. troops for fighting.
5. armed troops.
Question: 
Which is/are grammatically correct ? 
Correct them please if they are wrongly written.

Answer

A fight troop is incorrect. The rest are all grammatically correct.

Answer

Correct:
1. Combat Troops - Standard term for military units in combat.
2. Fighting Troops - Troops actively engaged in fighting.
3. Armed Troops - Troops equipped with weapons.
4. Troops for Fighting - Troops designated for fighting.

Incorrect:
5. A Fight Troop - Use "a combat troop" or "a fighting troop" instead.

Summary:
* Use Combat Troops, Fighting Troops, Armed Troops, or Troops for Fighting.
* Avoid A Fight Troop.