We do not understand how to perform the battle sequence with an attacking force of one infantry, one tank, one airplane, one artillery against two tanks, one infantry.
The attacker rolled two (2)s for the attacking units at (3). Does this mean (2) units are moved to the casualty strip and does the defender choose which units to be destroyed? Defender rolls a 5 and a 3 resulting in one hit. Who chooses the unit to be destroyed?
The receiver of the hits chooses which units to lose. In this example, the defender suffered two losses and would probably choose to lose one infantry and one tank (although he could, in theory take two tanks as losses).
The attacker suffered one hit, and will probably elect to lose the infantry.
That's why there is a so-called "infantry push mechanic" in the game, that encourages both sides to build (and lose) mainly infantry. Heavier units are for attack (not defense), to give your infantry an advantage over their infantry.
