History of Money, by Glyn Davies. p. 142.
What are the advantages of the new vs the old military service model?
The first advantage would be a greater degree of specialization, which is a common attribute of almost any successful business model innovation. With the introduction of scutage, the barons could specialize in making money, e.g. by improving agriculture, crafts, and trade within their domains, while the king could specialize in soldier selection, training, and military strategy.
Another one, would be a greater control over resources. The barons could now control the timing and scope of labor use, which in the old model could've been taken away from them at arbitrary times, e.g. during harvest gathering or seasonal forest clearing for agricultural needs. At the same time, the king gained direct control over army mobilization time, which in the old model depended on the willingness and ability of barons to provide requested manpower according to the kings needs.
Finally, scoutage led to growth of a new class of professionals - mercenaries whose only purpose in life was warfare.
The structure of this business innovation is similar to the transition undergone by the computer industry in the 1970-80s: from IBM enterprise model, where software and hardware were provided as one package with a series of periodic custom updates, to PC-based shrink-wrap software sales, a model Microsoft eventually rode to world dominance in 1980-90s. In both cases we saw a replacement of obligation-specific (in kind) transactions with obligation-generic (money) ones. As a consequence, a new class of specialists developed, mercenaries in the beginning 12th century, pure software firms in the end of the 20th century.
tags: business, model, innovation, history, software, industry, information, technology, computers