Like you I find the conclusions drawn by these authorities a little counter to common sense. I can't see how these women could be considered powerful. It sounds to me like all they really got was a nice funeral. The women themselves could have been considered prize property and their deaths more had a more symbolic effect than as an expression of these women's power alone. The artifacts that point to them as having warrior status could also mean they were killed an prisoners of war and were honored for that fact.
This is the first thing that leapt to my mind:
ROSS
Your castle is surprised; your wife and babes
Savagely slaughter'd: to relate the manner,
Were, on the quarry of these murder'd deer,
To add the death of you.
MALCOLM
Merciful heaven!
What, man! ne'er pull your hat upon your brows;
Give sorrow words: the grief that does not speak
Whispers the o'er-fraught heart and bids it break.
MACDUFF
My children too?
ROSS
Wife, children, servants, all
That could be found.
MACDUFF
And I must be from thence!
My wife kill'd too?
ROSS
I have said.
MALCOLM
Be comforted:
Let's make us medicines of our great revenge,
To cure this deadly grief.
MACDUFF
He has no children. All my pretty ones?
Did you say all? O hell-kite! All?
What, all my pretty chickens and their dam
At one fell swoop?
MALCOLM
Dispute it like a man.
MACDUFF
I shall do so;
But I must also feel it as a man:
I cannot but remember such things were,
That were most precious to me. Did heaven look on,
And would not take their part? Sinful Macduff,
They were all struck for thee! naught that I am,
Not for their own demerits, but for mine,
Fell slaughter on their souls. Heaven rest them now!
MALCOLM
Be this the whetstone of your sword: let grief
Convert to anger; blunt not the heart, enrage it.
MACDUFF
O, I could play the woman with mine eyes
And braggart with my tongue! But, gentle heavens,
Cut short all intermission; front to front
Bring thou this fiend of Scotland and myself;
Within my sword's length set him; if he 'scape,
Heaven forgive him too!
MALCOLM
This tune goes manly.
Come, go we to the king; our power is ready;
Our lack is nothing but our leave; Macbeth
Is ripe for shaking, and the powers above
Put on their instruments. Receive what cheer you may:
The night is long that never finds the day.