This answer needs some precision. You are using the Revelation 12 passage, as a position against the one from Ephesians. Let’s look a little closer ...
REV 12:7 Now war arose in heaven, Michael and his angels fighting against the dragon. And the dragon and his angels fought back, 8 but he was defeated, and there was no longer any place for them in heaven 9 And the great dragon was thrown down,
Here Satan is ‘thrown out’ by Michael and his angels. But now consider Genesis 3, which I will look at using Isaiah and Ezekiel ..
Isaiah 14:12 ”How you are fallen from heaven, O Day Star, son of Dawn! How you are cut down to the ground,”
Ezekiel 28:17 [snip] I cast you to the ground;*
In these cases it is God who is casting Satan out, ‘cutting’ him down to the earth. Are these the same? And, if not, how does this affect your answer? Ephesians 6 is Paul outlining the current (church age) situation, where the (evil) spiritual ‘forces’ occupy the heaven that is around the earth.
Now remember that heaven throughout the Old Testament is always plural (or more exactly, more than one). Paul talks about the third heaven, so we could safely assume there must be a ‘second’? Early Hebrew writings (non canonical) talk about 7. The other responses outline the ‘more than one’ heaven, so this side of the answer is well covered.
So, Satan was cast down from the highest heaven, where he previously had a role. But, all spiritual entities occupy the heaven around the earth, or in other words, the ‘spiritual dimension’. (Around us). And it is in this ‘realm’ where man interacts with that dimension, where man ‘sees’ angels, where Satan and the sons of god are seen in Job 1/2.
That ‘realm’ where principalities and wicked forces etc, as per Ephesians 6, operate, is likely this ‘realm’ around ‘us’, (first heaven?) or the heavenly realm between this and the highest heaven (the ‘second’ heaven?) (note the Q? marks, as this although could be argued, is somewhat speculative.)
But, essentially the ‘situation’ In Ephesians 6 can’t be considered against the Revelation 12 passage because that has yet to happen. This ‘war’ is yet to come, this can be seen when considering ‘end time’ passages from Ezekiel and Isaiah. (Arch angel) Michael has yet to be involved, and when he is, Satan will be thrown down to the ‘lowest’ heaven, with his angels. (The Hebrew concept of ‘head and tail’, Satan is the head, and wherever the head goes, the tail [naturally] has to follow.)