all pokemon the same trainer have same IDs. At this point when u use in golden rod lottery option where u need to get a poke with a speciefied id to get some rewards like expshare and masterball is impossible to get unless u are very lucky and have the right id. the lotery number should change each week but i dont see ingame what time it is or will it ever change...
Isn't that the point? I know it's been a while since I've played a Pokemon game, but I recall Pokemon you catch have the same ID. It encourages you to trade with a bunch of players so that you can have more IDs to work with and increase your chances of winning.