as most of thinks in game, that have too many looting options, also homuculous breed is based on low probability. We have in every breed 15 kinds of homunculous. Formula is probably based on calculation first looting basic kind (5 in total) and after formula looting with chance if homounculous will be general, water or luminious. So simple combinatory maths says 5! (5 factorial) and after additional 3!. And of course we not see if NCsoft introduce for some basic loot additional more or less probability as for general vs luminious.
So we can discuss that we need only time and resources. This is true. But this looting chance to get 1 exact homunculous moreover luminius will be tricky because everything is unpredictable luck constalation of STARS. Someone get luminious (exact that want) after 5-10 try and someone can try forever.
I am no crying, after 18 breed still no water or luminious Palo/Tanga, i will try and try. But things that need spend a lot of time and resources in dying game, soon or later go to ashes and people became frustrating. And answers that will saying that general is enought or so are pointless because all will want better things not basic. This is role of MMO games, to make progress. Lineage 2 is saddenly no MMO no RPG in basic anymore.