Fighting Spence next year is not the top priority of Team Pacquiao in fact there is a news that i've read (just can't remember the name of the writer) saying the Manny's representative is now actively talking and negotiating the camp of Floyd Mayweather for a possible rematch next year. For me that is the very practical move Team Pacman should be doing.
Spence would be the great choice other than Khan and people choose it.
Floyd Mayweather maybe cherry picking on his opponents but he fight Manny on a rematch it would still be cherry picking as Manny will be having a hard time aginst a defensive boxer like Floyd. Besides the money involve on this fight would be huge so expect Mayweather to give a go signal when the right time comes, that we don't know.
Spence like i said is not a healthy fight for the Pacman at this stage of his career. That fight is very winnable for Manny but he is also compromising his health in doing so. Fight against Thurman is ATH in term of blows taken from an opponent and it would be new ATH if the fight with Spence push through. Manny had already enough of the beating and should consider fighting opponents level with his age but equally entertaining also.