In the mission ZSC 32 + 2 Control Edessa, managing well your resources is essential. However, deleting an object / unit in a sector belonging to you gives you the resources spent for that object / unit back. Fine. But this also applies to dead objects / units. Which means that if you are under attack, and your defenses sustain casualties, you can delete those casualties and spawn brand-new assets, without spending a dime. This issue makes the sectors way too hard to seize.