It occurs to me with a booster preps now available there's no longer any reason to prep fewer glyphs. Humans get 200 CP worth of attack bonus, which outweighs your best-case gains from fewer glyphs. Orcs get a nice synergy out of extra attack boosts and will very rarely even consider anything else. Dwarves and elves get 160 CP and 140 CP respectively, which is pretty near their best-case scenario (plus dwarves desperately need any source of attack bonus, so I cannot imagine picking anything else as a dwarf now). Goblins, Halflings, and Gnomes all desperately need stat boosts to complement their conversion benefits so I can't imagine taking anything other than a booster prep for them.
It seems that these booster preps have edged fewer glyphs right out of viability.