If Calvert-Lewin had scored 8 goals in 5 games for us then I've no doubt that he'd be picked by Southgate.
As for Baldock not getting picked, are you really surprised? Baldock is too hesitant with the ball and doesn't put in an early ball into the box. He kills the ball's momentum, passes it back to another player, gets it back then crosses it in. So many times we end up going from having two strikers in or around the box against two defenders, to two strikers in or around the box crowded out by all the opposition who have got back during the time that Baldock has been faffing around. Watch him closely next time and you'll see this happen constantly in matches. It's infuriating to watch, particularly given that our main route of attack is crosses in to the box.
Not only does this help the opposition get back and defend in number, but the ball lacks pace. If he whips it in first time after the ball rolls in front of him from the initial pass, then the cross will gain some height and pace when it's whipped in.
Baldock isn't good enough for England. Sorry.
I do feel a bit for Basham, though he's not started the season as solid and consistent as last year.