I agree with @DLane, you can install the system today and start enjoying at least some of the benefits of smart system, with recent software changes it is easier than ever to setup the needed delay between zones to support the mechanical operation of the indexing system. The delay functionality (link) was intended for well pumps, but works just as well for your needs.
Until you setup the individual valves (worth it), you would have to essentially treat each of your zones as identical to each other (similar to the way your controller used to operate). There is some individual zone adjustments possible, as in setting one zone to run longer than the others, but should your system loose sync for any reason, the zone which needs water more would get less and some other zone would be over-watered.