I expect it would be normal for key players to suggest possible targets and be asked their opinion about potential recruits, eg character, team fit etc
Final decision would (or should) be with coach and head of basketball.
Once they decide on a player, it would be best to do whatever you can to get them to your club, including have coach and key players (particularly if they know them) contact the player to advocate for the club and try to convince them to sign.
So the club no doubt are discussing potential recruits with DJV (and Isaac etc) to check if any potential issues or if they can help in recruiting them. Doesn't mean any of the players are calling the shots, they will be involved in some way, depends on how they interpret the involvement in their own mind. Either way, no harm in letting them think what they want if it gets players buy in