#5 Get in a better third striker
Aubameyang and Lacazette both are amazing strikers and definitely will start the majority of games in the next few years. However, behind them is a big void. Welbeck, who is a backup to them is often injured and in my opinion not good enough to be a direct replacement to either of them. Nketiah is another talented option, but at 19 years, old not ready for such a big task.
In his case, I would recommend a loan, as he would benefit from some first-team football. However, another experienced striker is needed to displace one of the two if needed. A great candidate would be Joshua King. The centre-forward is very fast, clinical in the box and right now blooming up for Bournemouth. He got experience in a two-striker formation and with a value of around £26 million definitely worth to splash some money on him.