Given his views as expressed below it could be that the number and quality of the signings planned will depend on whether or not Wenger believes he needs to make changes at a fundamental level.
Seems that signing three players to introduce immediately into the starting XI would represent a significant step in another direction for Wenger.
The signings made last summer were of the squad strengthening variety, I don't believe that any of them were brought in to alter the structure or balance of the team.
For me, when you change more than three players in a team, you always take a technical risk because you change the deep structure of the team and the deep balance of the team, mentally and technically.