While I'm not going to say that it won't work, the words 3/4" feed, 30 PIS, and Rotors just don't seem to go together.
A rule of thumb I've read about at www.irrigationtutorials.com is that for rotors, you need 10PSI of pressure at the heads for every 10ft of throw you expect from the rotors. That means if you are designing for rotors to throw 30ft, then you have to have at least 30psi at the heads after accounting for pressure losses through filters, valves, and pipe friction losses.
3/4" polly sounds too small on multiple fronts. First, 3/4" polly would limit the total output flow rate of the system to 8gpm. Otherwise you will violate the 5ft/s speedlimit plumbers should observe when sizing pipe. Additionally, your pressure losses might be too much. At 8gpm, 3/4" polly will have a pressure loss of almost 6psi for every 100' of pipe. But 1" polly will have about a quarter the pressure losses for a given flow rate (i.e. 1" polly at 8gpm has a friction loss of a little more than 1.5psi for every 100' of pipe).