Unfortunatelly, you are right. This was already discussed on these forums, though without a decisive conclusion what can/should be done. But if I remember well, in latest patch something was done about Bulgaria's mobilization level.
Game is definetely balanced for an 1941 invasion. I am actually for giving players more options, early Axis invasion included. But in this game, Germany is not punished enough for doing it, quite opposite actually. Discrepancy in infantry weapons tech lasts a year more, with decisive blow against Soviet armies. Not to mention, that historically going for USSR in 1940 was out of question.
Last major patch (1.06) was in February, maybe an update is behind a corner. There are really some things worthy to adress (Vladivostok, positioning of Chinese HQ's etc.), maybe this will be one of them. Some info from devs would be welcome.