Just to clarify (and possibly nitpick), Carniflex (for Delera's) is not static, it's semi-static. Plenty of "I've run Delera's [arbitrarily large number] times and not gotten Carniflex
" threads/posts floating around.
As a personal preference, I take Toughness early. I prefer to be alive then to do "awesome" damage. Things don't hit too hard at low levels, and by the same token, don't take much to kill either. I'd say it's mostly preference. (If you were an Elf or a Drow, I'd advocate more strongly for taking it earlier, but you're a Dwarf, so w/e ^^)