Yes, you can, but it would be advisable to start praying that nothing binds in flight and you don't bang the stick too fast at the end of the flight. At peak amp draw, the digitals will suck lots of amp and pull the voltage really low.
Try this: get 4 digitals and one normal servos and run it on a 600mah pack that is 75% charged with a voltage tester, you will see how fast the voltage drop when you pull all the servos at one go. And that amp draw is only for no load, imagine you are up there flipping and flopping, the load on the servo will get a lot greater.