To some degree all military ideas are bad, so there is very limited scope for "speaking up". Militaries are not democracies. Orders flow downhill. In this spe

To some degree all military ideas are bad, so there is very limited scope for "speaking up". Militaries are not democracies. Orders flow downhill. In this specific case the guy on top wanted to invade for reasons. Yes, What objections the generals would have had would have been partly suppressed by the natural military doctrine (but that exists in all militaries) but equally the nature of their leader's personality would have suppressed objection. He was not known for changing his mind. Equally after the successes of 1940 it Likely wasn't as obvious a mistake then as we see it now. Had the UK fallen in 1940, and there being no second front, (and hence no North Africa) Barbarossa would have like succeeded as well.