Radak: This is a Mashal for the enemy, like "Ki Esh Yatz'ah me'Cheshbon" (Bamidbar 21:28).
2.
Malbim: Their punishments will not come naturally, that first the enemy conquers the cities of the field around, and then the gate of the city, and afterwards they destroy Beis ha'Melech. It will be the opposite ? first "I will send fire in Beis Chaza'el" (Beis ha'Malchus), and afterwards "v'Achlah Armenos Ben Hadad", and then (refer to 1:5:2:3).
2)
Who are "Chaza'el" and "Ben Hadad"?
1.
Rashi: They are kings of Aram. Malbim - Ben Hadad was Chaza'el's son.
