This makes sense, Viana liked to recruit within the league at Sporting, taking players performing well in a smaller team and adding them to Sporting. Make another team weaker and Sporting stronger. I think he's trying to do that here we have done that before but right now going by links our entire transfer list are players within the league who are performing well. He even did that with the next Sporting Manager Amorim was at a lower club.
When he signed , an article came out saying he does recruit from outside the league but prefers to recruit within as they are proven and can slot right in to the Sporting set up.
Looking at the targets which have been consistently linked they are all within the league.
Anderson - Forests best midfielder
Guehi - Crystal Palace best defender
Semenyo - Bournemouth best attacker
Tino Livramento - Solid right back
Wharton - Crystal palace stand out midfielder