We shouldn't send any youngsters out on loan so they can play in a shit U23 league all season but with the possibility of maybe starting a grand total of 1 or 2 starts in dead rubbers for the 1st team.
The Dowell and Williams loans are spot on. Those two players are getting regular games at Forest and Barnsley and will be much better for it. That's exactly what you want from a loan.
Connolly and Walsh have barely played at all at their respective clubs. So they aren't getting the games needed to improve and McCarthy/whoever the fuck replaced Redknapp is overseeing their development. They would 100% be better off here, even if neither player were to make a single first team appearance this season.
Loans aren't good in and of themselves. Some thought needs to be given as to whether or not the players are actually going to play where we send them. And even then, I'm dubious about the value of having them work with a dinosaur like Mick McCarthy.