And you could calculate that delay with something like this:
delay_ms = 3 / sin( angle )
So with this example, when the angle is 90 the delay will be 3 ms until the next servo move (91 or 89) and with for example an angle of 179, the delay will be ~172 ms. I suggest you use microseconds for more accuracy.
(Be carefully with angles 0 or 180, it will divide by 0 and your Arduino may explode
Oh and don't use delay() or delayMicroseconds() functions, instead look at the "Blink without delay" example to see how to do delays without those blocking functions.