Sequential combat resolution rather than parrallel combat resolution is the rule.
Knowing this, a skilled player will use his option to choose combats as the attacker to minimize risk.
For example, allow combats A and B to be set up.
Combat A, even if wildly successful will still leave units badly exposed if Combat B does not succeed.
Obviously doing Combat B first will help the decision on whether Combat A should be pushed.
Another example is G1.
2 FTR in the combat against the British BB and 2 FTR in the combat into AE. Both need to succeed if the Med is to be locked down. Doing the higher risk one first allows you to chose not to push the other one if the first goes badly. If the first goes well with minimal loses, taking more losses in the second is acceptable.
Now with the in house dicey and “tradition” of all round 1 at once, the above legal decisions are not as readily available.
Lets try a different example:
Combat D, E and F all need to succeed in order for any of them to be of value due to unit count, position, Victory cities, etc. By rolling all in parrallel, the attacker can call of all three if any single one starts to go bad.
As for those of you who don’t normally retreat as the attacker if things go bad, songs are written about decisions like that.