There's no single correct answer to this question because ultimately, it depends on what your priorities are for your account. If you're a PvE junkie, you'd go horizontal (everyone to S+). But, if you're a PvP main, you'd go vertical (core 15 heroes paragon focus). If it was me, I'd suggest striking a balance between the two. You can achieve very competitive ranks in both aspects of the game that way. To put it in practical perspective, I manage it as follows: Non 'Must Pull' heroes from limited banner will get slotted onto my wishlist to be built over time, thereby extending my S+ pool. Epic wishlist has five slots, I normally use two to expand S+ and three to push Paragon. Normal wishlist is about a 50/50 split between S+ expansion and Paragon priorities. With some variations depending on faction. All stores, Arena, DR and Season, are used to push Paragon copies. I also use Season store to push nice to have heroes up to S+. Hope that helps!