It would take upwards of 12 months to incorporate any advanced air defence system into a modern and professional military.
Training of Syrian crew is only half the problem the system needs to be incorporated into the existing air defence network which is difficult. Incorporation of the systems radar with other platforms using different missiles in the inventory and its communications systems need to be assimilated into the larger network. If the Russians operate them, then there is a certain level of language and communication problems that could hamper the effectiveness, unless they take out the Syrians completely.
The real question is whether the Russians will engage any Israeli aircraft. Which they wont.