You'll see the negative impact of 4 months break without County/FC cricket after all those Ramadan cup & corporate league. The game is built on momentum, which Arthur gradually built with constant practice & match application in last 12 months - now after 4 months, he'll have to start from scratch; starting form a team that'll be comfortably 2/3 KG heavier in average weight.
More matches never hurts the preparation, if work load is distributed properly. Also, the iron was red hot now to give "rest" to MoHa, Malik, Wahab for a series or 2 & bring 3/4 younger faces. What PCB selectors have done previously is technically picked youngsters & then they were played to fail - like playing at wrong spot, playing in wrong format/wicket, so that they can be dropped easily. On top of that, unlike IND, PAK mostly plays 3 match series, which hardly allows any flexibility to rotate squad.
You can't select seniors & then expect them to carry drinks & youngsters making the playing XI - to avoid such situations, what every team apart from PAK does is in such bilateral series, they "rest" few seniors, who are automatic starters. Like IND had dropped Bumrah & Rohit; AUS/SAF/ENG regularly drops their key players. What PCB selectors do is they pick apparent best XV with few youngsters & then make them carry drinks. This time luck favoured for JK/Raees that Wahab twisted ankle & luck for Fakhar that India hammered n 4th June - otherwise, his career could have ended with a debut at no. 6 in the sea rubber against SRL.
Ideally, PCB should have played 6/7 ODI with BD & send at least 5/6 new faces from CT squad in 16 member team - Farhan, Amin, Aga Salman, Mir, Yamin & a new fast bowler; dropping Azhar, MoHa, Malik, Amir, Imad, Ahmed & Wahab from the CT squad - if it even ends 0-6, so it be (though I think, barring Amir, change in other 5 will make the team better). That 5-0 drubbing against SAF didnt stop Aussies to rest Smith, Warner, Strac against Kiwis. And I am sure, had that series been there, BCB also would have played 3/4 new faces.