Most of the people outside Iran are not aware about the Military & security structure of Iran, for them IRGC & Iranian armed forces are the same. In my view he just wanted to say that the captives are the Iranian Security personnel.
If not then no need to send the pilgrims in worst security situation and in heated sectarian divide in Syria.
The bold part is enough to prove that you aren't well-informed about the situation at all. If you know 1% of what's going on, you would've already noticed that the FSA is claiming they are IRGC agents, not the Iranian army.
Why they would need deception tactic? To risk their lives for what? When they can safely send their agents by air planes landing in safe Syrian military airports, why they need to risk anything?
Indeed.
If not then no need to send the pilgrims in worst security situation and in heated sectarian divide in Syria.