Hi,
Can you show me an example of the guides getting shorter when you comb them?
The length and point count matters in a simulation. I would not worry but that though. Even if the strands have different lengths Moov physics will work more or less the same. What is more important is the point count. I suggest using a Detail node to resample the strands before the simulation. Also work in real world scale for better results.
It will also depend on the hairstyle, but I may suggest simulating the short and long hair individually.
Jeordanis Figuereo (Product Designer. EPHERE Inc.)