1-Alena isn't a CM, he is AM who is borderline attacker too. He might develop as CM down the line but won't play that position any time soon next season
2-We should really avoid judging deals just by trends, at this rate we won't sign any player. By this we won't sign from A.Madrid,Villarreal,Seville Valencia as most recent signings from them were all flops, Arsenal players too,players from Brazil and Italy too.
Everyone is his own case, there are ways to make conclusions but it should come second to watching players and honestly most those discussing him hadn't watched more than 300 minutes of him at best
Can he be converted into a workhorse?
From highlights I feel he is a workhorse, seem good on defense with good workrate but playmaking is one thing that doesn't impress me from his Youtube. But as I just said I prefer to watch him before judging