Both Beto and Scamacca are pretty big risks imo, and I'm not sure they have the upside of Balogun.
Beto - has had two seasons in Serie A scoring 11 and 10 goals in each. For all the complaints of Morata not being a great scorer, Beto is not either. Also it's not as if he's played for a terrible team, Udinese have some decent talents. He's also 25 so not a youngster with big potential. I don't think he's a bad player but more of a 4th option. Udinese also wants 25-30 million for him, so transfer fee isn't that much less than Balogun and more than Morata.
Scamacca - probably bigger upside than Beto, but according to transfermarkt the guy had 4 separate injuries this season (although it seems like it's mostly due to the same knee issue). Regardless, he missed a total of 172 days of football with injury - that's almost 6 months, including having knee surgery. Unless the deal is on a loan+option, big no from me as he would cost almost as much as Balogun. Even if he is available on loan+option, it still needs to be in place of Correa imo. Having Scamacca and Correa together is a huge risk that you don't get much from two of your strikers.
Based on the 4 options being suggested (Balogun, Morata, Beto, Scamacca) as 3rd striker (providing Correa stays), my preference is Balogun, then Morata.