How retrain affects units' experience?

[fant]

Hi all,

I would like to ask how retrain affects unit's experience. In the old TW:Rome, the new, additional units you gain from retrain has 0 experience. As a result, if your units have high experience, retraining and re-suppling the lost men will drag down the units' experience.

In MTW, say I have a units of 4 experience. Half of the men was killed so I retrain the unit, but the experience for the unit will still be 4.
My question is:
Though this unit appears to have 4 exp pt, but, are there any hidden records that will still remember that half of this unit's men is actually newbie, and make this unit to take longer time to have level 5 experience?

[Sitarus Originalus PM-30+]

good question... i think it wont take longer time to get level 5 exp.

[delra]

Chevrons are the average of all the men in the unit.

Youngsters start with no experience while the men who survided previous battles keep their experience during retraining.