Umar was definitely hard done by PCT management, starting from Misbah. And, he didn't deserve to be dropped at the age of U21 with 16 Tests and 999 runs (@36/66), while he should have been a PAK regular for T20 all-through, may be ODI as well.
But, it's really too much to stress that he could have saved the jobs of PAK Coaches, more precisely Mickey Arthur.
First of all, Arthur was sacked not because of performance only, rather PCB management wanted a change, and there is a massive pressure from PAK former players for a local coach - which will end in tears, but we can sacrifice two years to prove something that about 12 stints under Javed, Waqaur, Mohsin, Aquib couldn't prove. Otherwise, in current context, I don't think PCB will find a coach remotely close to the calibre of Arthur.
Having said that, Arthur himself contributed lot in his demise - he was too stubborn to adopt Asian game, he was too rigid with his tactics/combination regardless of condition or availability (of player pool to fit his tactics) and he decided not to learn from mistake. Final nail in his coffin was that he decided to compromise on selection issues, fitness issues, Captaincy issues - eventually that sidelined him behind Inzi & Sarfraz, he became a trainer rather than a Manager.
Coming to the examples that you gave - no, Umar Akmal won't have changed any thing, not a single Test result, in fact he could have cost more. PAK lost 4 out of 5 Test in UAE (NZ, SRL) because and ONLY Because playing XI didn't have enough spinners. I won't bother to explain you what a couple of genuine spinners (yes, batting at 10 & 11) can offer in Asian Tests, but let's focus on other areas. Umar Akmal would have been bigger flop in UAE Tests, because he is just not that type of batsman who can spend 6 hours in middle to reach 100 - most cases he would have scored quick fire 20s & 30s, before holding out, or being stumped; now please don't tell me that 20s & 30s were enough because PAK lost to SRL by 19 runs and to NZ by 5 runs; that little I know, but it doesn't work that way. PAK was short of one, some times two spinners in UAE, which cost them at least 3 Tests (out of 4 that they lost). If you analyze the 1st Test between PAK-AUS, there was enough runs (without Umar Akmal) for the bowlers to pick 10 wickets in 140 overs - a SLAO Spinner would have won that Test by Tea on day 5. So, it's not Umar actually - Mickey is almost alone responsible for those two series losses and he should have faced incompetence charges for fielding 3 pacers in 2nd Test (SRL), after the experience of 1st Test.
Coming to SAF Series - may be Umar individually could have scored lot more than Fakhar (not a big deal to replace a hack with single digit scores to be honest - even Sarfraz out performed Fakhar, FGS!!!), but the magnitude of the losses were so much that it won't have mattered anything at the end regarding series result. Also, PAK picked pacers by numbers, not by quality or combination - Abbas had a poor series (he wasn't fit) and apart from Amir, no other pacer were effective.
I would rather say opposite - only three stars in Arthur's resume (for Test cricket), were the ENG Series 2016, 2018 and the WIN Series - Misbah was MoS in first one, (& YK playing the innings of the series in decider) was instrumental with bat in WIN and the last Lord's Test was won by couple of gutsy innings, which is always beyond Umar's capacity. I would rather say opposite - had Umar Akmal played all 9 Tests, it was more likely that PAK would have lost more than 4 Tests that they lost. You are forgetting the fact that, an attacking batsman like Umar Akmal is an asset for a top Test team to enforce the win, not for a ranked 7th team, whose main effort is to avoid a defeat - and Arthur has to take major chunk of responsibility for this free fall of PCT, from No. 1 position as late as OCT 2016, most of what was achieved by a PCT managed by WY.
In contrast, what kept Arthur in job for one extra year was PCT's win in CT - a tournament where he almost forcefully dropped Umar Akmal, that eventually kept him in job till 2019 WC. I am a fan of Umar Akmal, do agree that he was hard done by and do feel that PCT will be a better team with Umar in XI, may be as WK-batsman as well in T20s - BUT, what you have written here is simply absurd - Umar Akmal is too ordinary to be praised like this.
