I was answering his question to why someone would waste at least 30m for a perfect homunculus which is to get a good stat. Yes, it's random which is why you waste 30m and use a Homunculus Calculator to calculate to see whether it's a good Vanil or not you can do this by leveling it to level 20 which is like 30 minutes to an hour and then see it's progress and if you dislike it you delete and try again. Basically, It's not random since you have Homunculus Calculators to do the stats for us.
Back on topic...
If you check the IRO wiki and search for the Homunculus guide you will see that it is controversial as to whether Stats affect the chances to get a certain type of Homunculus...