Well, if you're serious about this option and about staying on the balcony, then okay, let's work on the first plan. But it's probably better to put the archer on the balcony as well – if someone appears in the hall, they'll take him out immediately.
Let's go with the balcony, together with the archer.
Added 11 minutes later
The only remaining question is the position of the archer and Meretta on this balcony. I placed her near the stairs so that she could react if anything happens, and him further away so that he wouldn't be reached. Plus, from there, he will be able to shoot at some part of Area A. And Meretta will probably be able to shoot at some of the squares south of the entrance to the hall if the door is open. But maybe we can rearrange them somehow?
Небо – угроз не слышит
Небо – ведёт особый счёт
Небо – тебя найдёт