The answer to this question is complicated. Basically, Universal spends about 20 to 25 percent of an attraction's development budget on soft costs (design, admin, management etc.). Disney can go up to 30 to 40 percent in some cases. The reasons, in part, for Disney's higher soft costs are R&D as well as layers of wasted management labor costs. Universal will rely heavily on "free" work from its vendors to bid on a much less developed concept design package. The vendors will have to develop these bid packages to the point that Disney would have released its bid packages (whether these bid packages are going in-house or out to a sub makes no difference). For the Universal vendors to get these design documents up to the point of putting in a decent bid they will need to dedicate some resources to flesh out the basic concepts communicated from Creative Studios in minimal drawings and beat lists etc. So what ends up happening is UC gets a lot of free design work because these vendors want the job and will develop the basic concepts to a level that they can estimate budget and schedule requirements. Disney will have already gotten that far before submitting its bid packages.
As far as red tape and bureaucracy Disney wins big time on that one. Universal has its fair share but WDI's bloated management structure and recent history of hiring lower grade talent, just because they may hold more college degrees for example (I am positive that, were he alive today, if Walt Disney himself were to apply at WDI he would be turned down), makes Disney extremely inefficient.
The fact that WDI allocates a much higher percentage of project resources to R&D also adds to their higher costs.
There are more reasons but that will give you a start in understanding the differences.
