If kyrie decides to resign do we need to trade for Davis or can we be ok with a healthy Baynes and sign someone like robin Lopez ?
It would depend on your evaluation of Horford. If Horford is later part of his career Duncan seeking to upgrade his spot might not be the best use of resources. Think about old man Duncan beating LeBron's Heat team. Yes Kawhi was rightfully awarded the Finals MVP, but Duncan was the spiritual head of that team. Elite experience and intangibles are difficult to replicate.
That being said there is no denying that present day Anthony Davis is a world's greater player than end of career Duncan. I am always going to say if you have a shot at Davis, you take it.