What Arsenal needs is a sharp finisher who will always be there to score as many goals as possible when the opportunity comes. Arsenal also needs to have more players on bench for easy rotation so that the work load wouldn't be much on the players in order for them not to end up dropping point towards the end of the season.
Arsenal in the last three seasons has indeed been weak in the front line because they do not have a striker who is productive in scoring goals, if they do not find a striker who has the sharpness in scoring goals then it will be difficult for them when they expect victory in crucial matches.
I saw in a local media article that Arsenal has reached a personal agreement with Benjamin Sesko, but on the other hand there has been no official statement. I think they have to move quickly to get a new striker in order to strengthen their strength for next season.
But some observers think that Arsenal has obstacles in the final agreement on the price because Arsenal considers the player they are targeting to be priced high and they are reluctant to agree to it.