It doesn't take four months to recover from Malaria, more like four weeks. Quote from late July:
"I came home to London two weeks ago and then found out I had malaria. I was ill for a week or so, but now I am back training and feeling good now. I knew it would take a few days and knock me down and take everything out of me. I also knew I would have to work hard to get my body back again. But I’m okay, fit and ready to play football again. That’s the main thing."
That was well before the start of the season, he had plenty of prep time and certainly by the time he was dropped (11 games in to the season) this was a long since expired excuse.
Again, Poch didn't go for Soldado and Townsend, after playing Ade for 9 of the first 10 league games he went for Kane and stuck with him. If he'd stuck with Ade instead, like you would have preferred (even in hindsight), we would not have had that remarkable Kane season.
I'm going to stick my neck out and suggest that for Ade to have gotten anywhere near Kane's return would have been miraculous. For you to say we'd have done better with Ade than Kane is somewhat moronic.