Well I can tell you this, we had a rogue in 3.5 who maxed out his UMD and took the feats Magic Device Attunement and Dual Wand Wielder. After that, we no longer needed a wizard because he could do what ever we needed done.
Wands are much easier to UMD and more affordable than scrolls in bulk besides. They are limited to 4th and lower spells, however. So you can get away without a arcane caster up to about 10th level before the limitations start mounting up. There are a lot of 5th and higher spells that make life much more tolerable for high-level groups.
That design is especially handy at blasting magic but there are costs.
*edit* The design is also somewhat illegal -- double wand wielder requires the feat Craft Wand as one of its pre-requisites. No Rogue gets the necessary Caster Level 5 to purchase that.