Let me make you sure of something,if they were really soldiers,they would have killed dozens of those terrorists,not being their hostage without fighting.It's not something new,FSA,abducts civilians and says they are soldiers.Like those 5 technicians who were taken hostage they made them confess they are fighting for Iran,but after Turkey meddled and they released them.
Why would Iranian soldiers chill around those dangerous area without guns?
One thing else,according to defense pact between 2 countries,Iran can send soldiers there.But we haven't yet.
But on the opposite side,there are merceneries from KSA,Qatar,Libya,Jordan,Afghanistan and so one,fighting in Syria.