We've had our hand forced by Sané getting injured. I've wanted us to sign an extra winger/forward since the summer, which is why I didn't exactly want Sanchez but wouldn't have said no to him either. We have five attacking midfielders (Sterling, De Bruyne, Silva, Bernardo, Sane) when everyone's fit, so I understand the signing now Sané and Jesus are out.
Plus, with FFP 2.0 looking like a possibility, it makes sense to do our business now and then tighten the purse strings in the summer. Right now, if Laporte and Mahrez come off, we're looking at going into next season with a nearly-complete squad. Fred from Shakhtar and another left-back will basically be all we need to do in terms of recruiting new players.