Book Title from 1970's-1980's - Military SciFi Collection of Tank Short Stories

Looking for title of collection of short-stories involving tank/tank battles. Pretty sure it had a tank on the front cover.

Two distinct stories I remember:

#1: Injured soldier stuck in a cave on Mars (or another planet) has verbal back-and-forth with a malfunctioning sentient tank that is just out of kill-shot range. The story ends when the tank realizes it can disable safe-guards, get a running start, and lob a shell/grenade the extra 50ft needed to kill the human. Tank registers satisfaction that the annoying radio emissions from the human have stopped.

#2: Enhanced super-soldier has been retired/exiled to a remote security enclosure out in the wilderness. Society used him for combat, then discarded/were afraid of him after the war. A female assassin-type somehow eludes security protocols and gains entrance to his compound. We realize that she’s there because the super-soldier killed her brother – who was a brain-in-a-tank, on the other side during the war. Lots of back-story, regrets, enlightenment, etc. She dissapears one morning, leaving the device that allows the super-soldier to escape his confinement.