1)
Why does it mention tall towers?
1.
Radak (14): One who has in a plain a tall tower, or walls of a fortified city (also his pride will be lowered in front of Him). Malbim - they trust in strong towers; this corresponds to "Ga'eh va'Ram" (12).
2)
Why does it mention a fortified wall?
1.
Malbim: It is less secure than a tower; this corresponds to "Nisa v'Shafel" (12).
