Synthesis/Breeding question

In synthesis or breeding is it better to level the parent monsters up before breeding/synthesis or does it matter?

as long as the monster is level 15 it doesn't matter for breeding. synth it just matters what grade it is, but even high grades wont guarantee a high grade outcome.

So level and stats of the parents doesn't matter in either?

the whole point of breeding is to raise stats, so lets say the parents are both D- grade then then child is going to better (probably a C or C+). but the level wont make a difference