Sorry, I am not answering your question directly, but I remember I've read some time ago an IEEE paper with detalized analysis of CML divider (basically checking the self-oscillation frequency for  different W/L sizing of input diff pair and latch with fixed bias current) and if my memory serves me right, the conclusion was that sizing them equally is NOT optimal.

If anyone remembers the title of the paper, please post it here, it would be useful to re-read it..   Or maybe if you have some free time - make a quick test and let us know te result