I think the mistake is hoping the skillset is exactly like Dihno's doesn't have to be. Here is a preliminary list of players I think can all comfortably take over from Dihno if given 1 year in the system.
It's impossible afcourse to find a perfect copy, but anyways. You took the effort to compile the list least i can do is to cover them all. Mind that i'm looking at it from Fm, i havn't seen any games of most of these players, so it's a superficial impression to take with a grain of salt as reality might be different, i leave it to you to educate me where Fm might fall short
Savic: looks more like a ball playing defender, doesn't have so much going forward by the stats
Wiegl: couldn't find back at first, but i think you meant Weigl who is a DM for dortmund. looks like a promesing youngster but would fall short for us at this age imho, not quite there yet but one day he likely will
Fabihno: Looks very good to be fair, practily perfect replacement at young age
Llorente: not enough going forward imho, again more a ball playing defender
Torreira: couldn't find him back in Fm
Lemina: looks very good and is young, but is Juventus going to sell?
Arthur Melo: another good find at a young age
Frenkie de jong: just not a defensive midfielder imho, doesn't have what it needs in defense
Jaoa Mario: more an attacking midfielder, doesn't seem to have the required defensive skill
Nicolo barella: another one that woudl lack the defensive skill
the 3 players above are also very young, they could become different players and perhaps work on defensive skill, though i deffinatly don't see de jong ever become a good DM.
Mikel Merino: looks good, he seems to trade off a bit of defensive skill for being a better passer but that seems ok, he's fairly young too.
Fred: looks ok, but perhaps more a player for a somewhat more forward position or perhaps even the wings, think Pep would have fun with him since he seems 2 footed and skillfull enough to even play as fullback, perhaps you could train him practicly every position on the pitch and then have him as a superb option on the bench.
All in all, i have to grant it to you for atleast providing a few good options we could go for strait away and who are at an interresting age. Fabinho, Lemina, Merino and Melo look quite interresting and likely available besides that they are fairly young still. And if Fred isn't too expensive perhaps we could buy him as a toy for Pep, he might become our second Delph.