I think that is good advice Erwin. I prefer challenging scenarios where my opponent has the clear advantage, but one also has to keep in mind that in the real world plans and objectives are not a set in stone, they often change as the battle develops.
In reality if a company commander is incurring unacceptable losses because it turns out that the enemy has a stronger force than expected higher command will often call off the attack and allocate assets/reinforcements required to complete the mission with minimal losses.
I try my best to complete all objectives set out by the scenario designer but if my planning results in an unjustifiable amount of friendly casualties then I quit the scenario (Battalion Commanders orders) and accept that I have met my match, or, most usually, rethink my tactics and try again.