^My point here is - Are you able to make him understand the pluses and minuses of each language? Will he understand? Are getting marks the objective? Or something that may help him learn a culture is important? Career advice? If you do end up explaining all this - Do you seriously believe the kid would be able to judge what is good at this point.
Now, lets say your company has self-improvement programs and they ask you to learn one of these. Are you (leave aside cases where one just wants it done and dusted) seriously able to judge what would be good for you, so easily?
*** This is not for Toocool's kid - But generally most kids mentality,
At this point, for the kid the most fanciful sounding reason would be the deciding factor. If someone throws a scare about a language, he is likely to switch . If someone tells him the teacher is strict & beats up students who dont study, he might switch, someone tells him the teacher is often on leave, he might want to switch, his best friend or group wants to be part of a particular class, he will want to switch.
*****
In conclusion, my view is that what you learn now cant really a deciding factor for career at so early an age. Its only for scoring marks and/or learning about a culture (provided they would teach something of that). But, having said that, one needs to definitely involve and decide or help decide what would be good for him/her as they have not reached an age wherein they would be capable of judging whats good for them.
Maybe the kid might make a wrong decision, but so can toocool. (no offense lol)
It's not life and death, only 5th grade, He can always change if he's not comfortable now. Maybe if toocool is willing he can keep an eye on the kid's progress, and if realizes that german isn't working he can talk it out with the kid for a possible switch. Board exams are 5 years from now. But at least he will be satisfied he did what he wanted to.
Everyone is allowed to make mistakes, let the kid make one, it's a harmless one.