Pudding%
The issue with Mayna vs. Archwinger is due to her only being able to have 2 shots on screen at a time. Though her power is higher, less shots would actually connect due to him spawning more bullets immediately. Lyll gets away with this due to being able to have 3 on screen at a time.
That's not to say it's impossible to kill Archwinger with Mayna, it's just riskier.
There's also the fact that, as you mentioned, you'd need to stay at an inn an extra time in Pochi's area to equip the Power Knuckle after suiciding against the Mimic. Unless you wanted to attempt Archwinger without it.
Add in that Pochi's area is done 2nd to acquire the 50 Gold on the way so we can purchase the Key Wand on the way into Xemn's area. Doing Pochi's area 3rd would mean buying it on the way in to Mayna's area, which would require an additional Inn trip to equip that.
...plus the manipulation going in to Xemn's area only works with the Power Knuckle, and I'd have no idea how to get it to work going in to Pochi's area with Mayna since her bounce is much lower than Lyll's and her attacks do more damage by default. I'm not saying it's impossible, but it would all have to be redone which is a painstaking process. Especially for a route that would lose at least 20ish seconds from 2 extra trips to an Inn (plus the extra 20 gold that would have to be farmed)
That's not to say it's impossible to kill Archwinger with Mayna, it's just riskier.
There's also the fact that, as you mentioned, you'd need to stay at an inn an extra time in Pochi's area to equip the Power Knuckle after suiciding against the Mimic. Unless you wanted to attempt Archwinger without it.
Add in that Pochi's area is done 2nd to acquire the 50 Gold on the way so we can purchase the Key Wand on the way into Xemn's area. Doing Pochi's area 3rd would mean buying it on the way in to Mayna's area, which would require an additional Inn trip to equip that.
...plus the manipulation going in to Xemn's area only works with the Power Knuckle, and I'd have no idea how to get it to work going in to Pochi's area with Mayna since her bounce is much lower than Lyll's and her attacks do more damage by default. I'm not saying it's impossible, but it would all have to be redone which is a painstaking process. Especially for a route that would lose at least 20ish seconds from 2 extra trips to an Inn (plus the extra 20 gold that would have to be farmed)