Voynich Welsh Numerology

[-JKP-]

I started with Leo, because that's my sign.
The zodiac sign Leo in Welsh is y Llew (lit, Lion). You've translated it as Cenau, which properly means cub or pup.
You seem to have done this for all the signs - you've found a Welsh word that has a vague approximation to the meaning you're trying to force upon it and that has a number value you need.

I mean, why would Pisces be "water" and not y Pysgod?

You've put your finger exactly on the problem, David.

Cherry-picking the results to support the theory is bass-ackwards. The data should lead to the results not the results being extracted to fit the theory.