Thanks for the translation comment Don. The PD, on any translation, says that of all the things wisdom prepares or provides toward a blessed life, friendship is by far the greatest. Not a good and useful means among equally-good means — the single greatest one.
Friendship is, by Maxs's account, additive in exactly the way ice cream and a fine view of the sky are additive. More trust, more years, more depth is always better, other things being equal. If additive goods are structurally barred from contributing to a "perfect" or "complete" life, and only katastematic pleasure can clear that bar, I don't see why wisdom would single out an additive good as its single greatest tool for reaching blessedness. Does "additive" really disqualify a good from being central to the blessed life, or doesn't it?