If Mourinho does come in after this season, Ibrahimovic is a no brainer. Would be the perfect signing. The two of them have a very good relationship, Ibra is still up there with the best forwards in world football, and he'd be able to be a starter next season and then possibly the year after (rotating with Martial) until Martial is developed enough to become the main, first choice striker. Martial and him teaming up would be wank worthy really, even if it's Mourinho's style. Struggle to think of any striker around that is more suited to us at the moment. We all know Martial will eventually become our main striker, but for now, he's brilliant on the left and should stay there. Rooney has done really well lately, but is aging like Ibra is so who knows how long he has left, and regardless, Rooney isn't physically imposing enough to bully defences like he used to, and I can see Mourinho using him as a 10 a decent amount anyway. Ibrahimovic will be perfect for bullying defences and leading the line. Will also be the catalyst signing needed to really pull us out of the current situation. He'll probably retire in a few years, but on a free, just paying his wages, it seems like the perfect signing.
Saying that, we'd still need to sort out the right wing position where we don't have anyone who plays there as their main position. Not even really linked with anyone for that. It'll come though.