From Khaled: "The rank of a Field-Marshal is only awarded for exceptional performance of a general, as in winning battles!
In peacetime, the rank is rarely awarded.
But the "rank inflation" as my father used to call it in the 1960s, came from Egypt, and infected the Syrian Army upon unity with Egypt.
"Rank inflation" has serious adverse effect of creating a top-heavy armies and complicating the chain of commands, in addition to reducing the quality of army command at all levels and creating a non-functional expansion of the officer ranks.
It is not clear whether the Syrian army gave up this practice, although there are signs that its operational officer corps seem to have become more professional and specialized, no doubt due to the tens of thousands of Soviet and Russian instructors who were deployed in Syria over the last five decades.
One notes that even Hafith Al-Assad did not promote himself beyond the rank of a full General ( عماد / فريق أول). President Bashar Al-Assad is a Marshal, as one notes in a photograph below [above]. "