Artillery batteries are intended for engaging surface targets. They do not pose a threat to aircraft.
The combat team tries to secure their two (short) ton weapons crate by catching it with four people, who would therefore have to somehow carry 500 lbs (450 kg) each.
Assuming 'small arms' means M4s or M16s and sufficient ammunition, 2 tons would be a few hundred rifles at most. This wouldn't even be enough to arm their minimum estimated number of rebels, let alone their high estimate of 5000.
A Search and Rescue helicopter would not be sent into an area where a friendly aircraft was just shot down, without it having been secured by friendly forces first.