Why can we have 12 AD/20 AP but not 18% AS or +15 Health at level 1?

Preseason patch (8.23) is knocking our door -- coming 21 nov. --, and yet no sign of a proper Rune stat/Stat shard polishing/balance. Armor and MR choices are still underwhelming on PBE, and there's no 4th option on the middle row, meaning we cannot pick 2x Health or 2x AS, despite having a 2x AD/AP option. If you ask me, seems like bias towards Assassins and burst Mages.

current stat shard choices on PBE:

Rune paths no longer dictate stat bonuses Stat Shards:

Row 1: 10 Adaptive (6 AD or 10 AP), 9% Attack Speed, 1-10% CDR (lvls 1-18). Row 2: 10 Adaptive (6 AD or 10 AP), 5 Armor, 6 Magic Resist, (We’re debating adding a 4th here). Row 3: 15-90 HP (lvls 1-18), 5 Armor, 6 Magic Resist Important note for clarity: Rune paths themselves no longer grant style bonuses; you now get those stats from Stat Shards.

Note that those changes belong to the upcoming preseason patch and have being tested for 3 weeks already.