Clones, with two exceptions, grow at double the rate of other humans, by design to have a large batch of adults in 10 years.
Seems like they wouldn’t be able to grow very many clones in 4 years. Don’t they say in AOTC that the army was 200,000 strong with 1 million on the way?
For some reason I thought they’d established there were 5 years between AOTC and ROTS.
Neither the films or either Clone Wars shows really specify how long the Clone Wars lasts, so I usually headcanon it to be 5 years. If you push TPM back to 34 BBY instead of 32, everything else falls into place and allows a larger period of time for the Clone Wars, without mucking up the rest of the timeline.