It's still early days, and for an u20 striker he had one of the best goal rates in Brazil so he should make it in Europe. Better than Gabigol and in the same category of successes in Europe like Jesus.
The only problem is technically he is not spectacular, and it may be a case of him being a success in Europe but at a more direct side.
I was having a bit of a dig at the City group though, and here are their 3 recent Brazilian signings in order of potential at time of signing.
1. Kayky - 5m - Failed so far. Loaned back to Brazil
2. Metinho - 5m - Failed so far. Loaned to Rotterdam
3. Savinho - 5m - Huge success in Spain. But failed first season loaned to PSV.
So a couple of points. The first is the obvious one, that Savio failed in the weaker Eredivise to make an impact. Had we signed him, at that point in time we would have claimed he was a failure.
The second is the fees. For a club like us it would be better to sign high potential Brazilians (and the three above were not the highest prospects like Vini, Endrick or even Angelo Gabriel) earlier and spread the fee over a few 5-10m mark players at 16 and wait till their 18 to bring over, rather than go big and compete with the elite tier spenders.
From this example above only 1 in 3 worked out, but then with the spread accounted for excluding wages, Savio cost just 15-20m.
So yeah. Plenty of examples of Brazilian players still going for those 5-10m fees and growing into good players in Europe. Matheus Martins, the Brugge striker signed from Brentford and even Luiz Henrique of Betis who was sold back to Brazil at a profit.
Once finances are better to consistently buy, maybe look at this route.