I’ve Magico A3’s, not A5’s, but perhaps a similar situation to yours. I need to place speakers pretty close to a wall. I decided to look at non-ported speakers when shopping for speakers, due to the closeness the speakers would have to the wall behind them, and having read ported speakers did better with more room behind them. I called Magico and inquired how close to a wall you could place their A3’s (non-ported) and still anticipate good performance. Their response was to place them at least seven inches from the wall.
The back of the A3’s I eventually purchased are presently sitting about 10" from the wall. They are located about 7’ apart on the long wall of a 21’ x 13’ room. That seems to provide enough side space, as Erik mentioned, is needed for Magicos. To my ears the soundstage is decent.
How the Magico’s might compare to the other models you are considering in respect to speaker placement I can’t help you. You might consider calling the other manufacturers. Another good source of information is speaking to the person who sets their speakers up at shows and asking what you can get away with with speaker placement. The person I spoke to at Magico just happened to be the one who did do their shows for them. Good luck with your purchase.
Mike