#3 Joining his former teammate Aubameyang
Dembele's time at Dortmund has arguably been the best year of his career, providing his teammates with 14 assists and 8 goals in just 38 games. Surprisingly, it was his first year at Dortmund.
And even more surprisingly, he had assisted Aubameyang 10 times in all Bundesliga games in a single season, considering the fact that they have never played together before and the 2016-17 season was their first together.
Dembele and Aubameyang's coordination and understanding were far better than any of the Bundesliga duos, and no BVB fan expected them to leave just next year. Auba has some great positioning skills, and despite his weak physicality, he has managed to score some beautiful headers.
He would absolutely love to have Dembele at Arsenal and could probably help the Arsenal transfer team in convincing Dembele to join the North London side. A healthy offer from the Emirates could certainly bring him to England.
With Dembele, Arsenal will look way stronger. The most likely system would be a 4-3-3, with Auba and Dembele on the wings with Lacazette. The team can completely depend on the front three for goals.
Dembele creates amazing goal-scoring chances, and Aubameyang has been a top striker for his clubs and country. Lacazette hasn't got enough chances at international level, but the Frenchman has scored 20+ goals in every season he played for Lyon. He has scored some quality goals for Arsenal too, and his partnership with Aubameyang can be of great help for the North London side.