The Brazilian is delighted with the business he and manager Mikel Arteta managed to get done and believes it has set the team up for success this season.
"I think we improved the squad's quality and physicality," he told the club's website. "Thomas, who we had in our plan for the future, when me and Mikel sit and talked, I think you get all the players who we really focused on.
"If you see Willian, he brings us experience and a very special physicality in terms of speed. If you see Gabriel, he gives us a lot of physicality and presence. Dani, quality. Thomas, physicality, quality and mentally he is very strong.
"But in the end if you see all these players we brought to the club, they are very good here (points to legs), but they are better here (points to head) which for me is very important because when you talk to the players, they have a lot of ambition, they are excited and they are hungry to win a title again.
"This, for me, is important to have in the players to not only be good here (points to legs), but good here (points to head). And they are."
New arrivals weren't the only order of business with new contracts for Pierre-Emerick Aubameyang, Bukayo Saka and Gabriel Martinelli secured in the offseason too.
Edu believes tying three key players down should prove equally as important as any of the new additions.
"This is another good point I want to mention because normally people are talking about signing players but for me and Mikel, we dedicate our time to what we have at home," he added.
"So we have to renew players, we have to give our respect to the players we have here, so let's do it as soon as possible. If you see, Martinelli was the first one we did even before the window, Bukayo was during the window and Auba was in the window as well.
"Those three, in my plan, was to try to get them done before the window even opened but of course there are negotiations, there are talks, there are meetings but we did it and it's an important point as well."