Greek mythology

Did Gods favor a person or an army at times?

The race of Spartans were said to be offspring of the god Ares.

Yes. In the Trojan war Athena, Hera, Haphaestus and Poseidon were for the Greeks. Apollo, Aphridite and Ares were for Troy. Also Athena favored the Greek heros Agammemnon, Achilles and Diomedes.
(Sorry I like the Trojan war alot)

To paraphrase something i heard once (and i wish i could quote it directly and give credit to whence it came) ....

May the gods stand silent, and let the arm of flesh decide !

Sometimes the gods favored entire armies, like at Troy, but usually they had favorite humans. You were favored by a god or goddess if you were related or if you had done them a good deed.