Here is an opposing argument.
It is evident that we don't have a reliable middle/lower order batsman who can score at decent rate (40/100 stats as you say). We know this since we have tried Talat, Asif, Iftikhar, Danish, Sarfaraz, Malik, Shadab, Faheem, Nawaz to no avail. Only Haider and possibly Maqsood are yet to be tried at middle/lower order.
But when it comes to opening, we haven't tried anyone in place of Imam. Who knows, maybe Haider,/Sharjeel/Farhan can maintain 40/100 stats as openers. We won't know until we try them out and this is the perfect time for experiments as 2023 is still a few years away. As I have posted before, we can always turn to Imam if things don't work out.
This series has established that we are 5th best side in ODIs (finished at 5 in WC as well). We cannot topple the big 3 (and Newzealand) with likes of Imam (80 sr) opening the innings.
It's a bit confusing because you make several good points. I'd be open to allowing Rizwan to open the innings to accommodate two aggressive batsman in the middle order, Haider and Sohaib.
I can think of a few options which can occupy positions 5 and 6:
1. Sohaib Maqsood - aggressive, good strike rate, good player of spin and can finish it off as well
2. Haider Ali - not a middle order batsman but he brings genuine aggression to the table and plays with an attacking mindset.
3. Sarfaraz Ahmed - has been tried in the past and didn't succeed, an option nevertheless.
4. Imad Wasim - boost Imad up the order and play him as a batting all-rounder similar to Stokes for England and see what he can do.
5. Rohail Nazir - young and keeps things simple, but match experience is a question.
6. Saud Shakeel - doesn't bat at a high strike rate but will bring runs consistently.
My personal decision would be to have Maqsood and Haider at 5 and 6 respectively.
If our batting does well up till the 40th over (around 250-ish at 40 overs), send out Haider and Sohaib and allow them to bat freely and aggressively.
Sohaib and Haider are necessary in my mind.
I think the combination we should look towards is:
Mohammad Rizwan (wk)
Fakhar Zaman
Babar Azam (c)
Sohaib Maqsood
Haider Ali
Imad Wasim
Faheem Ashraf
Mohammad Nawaz/Usman Qadir
Haris Rauf
Shaheen Shah Afridi
Hasan Ali/Hasnain
6 bowling options, each capable of giving you 10 overs.
Depth in batting, and a middle-order capable of finishing.