They are soldiers who come to the battlefield armed with their respective murderous weapons.
In a document about "Prepositional phrases and commas" it is said that we are supposed to add a comma before the Prepositional phrase, if its location is away from the noun it modifies.
Here in this above example, "armed with their..." is about the soldiers and not about the battlefield. Should I use a comma before "armed?" It doesn't feel good to read it with a comma though. I am very confused about commas. Any good suggestions to read for learning punctuations better?