Hello Udo,
There's no way of telling which build is really newer in this particular case.
OTA 39788 was released to the public later than 33608 to the garage but on the other hand it's usually that way that OTA is tested for much longer period of time than the garage builds.
I cannot upgrade from 33608 to 39788 that's for sure. And I'm kind of happier with 33608 because with 39788 I've had more bugs than usual.
Liebe Grüße
Lukas