First, "forum approved" builds do not make oversights like that. Trust approved builds.
But here's what's going on...
DDO is not D&D (at least not same rule set).
Spells do require Stat = {10+(Spell Level)}, yes. But in DDO,
any way you can get to that value works. Guildship Buffs will add +2, so you'll be at 10. Then, either Owl's Wisdom spells/potions add +4 (for 5 minutes), or gear adds "permanently" (while equipped) (not that these don't stack with each other, as they are the same type of boost). Then there are Tomes (but that's usually later), and some other possible bumps.
Bottom line, easy to get the job done despite starting at stat = 8.
Also, Rangers don't get CLW until Ranger Level 8 (Character Level 10 w that Trapmonkey build), so you have some time to find a good Wisdom item.
If that seems like a hassle, drop 1 pt of Strength (from 16 to 15) and add those 2 build points to Wisdom. That will get you thru Character Level 12, as you won't need Wis 13 until CL 13.
Otoh, you can dump trapping, take minimum Int, and use those points (but trapping is pretty handy).
(Also, don't miss the
Elf and Dwarf version here - no "best" of the 3 versions, so just go with what looks fun to you. (Drow version requires a premium Enhancement tree, not that one.))
"They" tend to be leet players who are trying to squeeze the last 1% out of DPS optimization. Both work fine. Khopeshes and scimi's (and Dwaxes) may be easier to find than good maces. <shrug> That's where it's easy to swap a couple feats (Improved Critical:Bludgeon vs. IC:Slash) and make it the build you prefer.
(I like the Elven Dex/Displacement build best, but for a 1st-life you might find one of the Strength builds easier, since Encumbrance can be a problem for a new player. ymmv.)