I find it very hard to believe if people would actually give you these Pokémon, if they did they're probably hacked. There are a stupid amount of people making unrealistic trades & it annoys me, I've been looking for a Munchlax for ages & all I've seen at the GTS is:
Lvl100 Palkia, Palkia any lvl, Dialga, Latios, Manaphy, Raikou, Mew, Jirachi, etc. The one time I saw a reasonable trade for a Munchlax was for a 9 or below Chimchar, unfortunately by the time I made the lil Chimchar the trade was gone.
I did manage to get a Bonsly & a Glameow over GTS yesterday, so I'm pretty chuffed about that! But in any case, I'm pretty annoyed with all these unrealistic trades, makes people like me with proper trades seem really mature or something :S