Masukan Tangan then, are the beginning of my answer to the dilemma of footwork being slower than hand attacks.
The reality is that footwork is slower than most people's hand attacks and once in range footwork is typically on a 2:1 or 3:1 ratio. As a result a good fighter will need some other way to respond to hand attacks. Most utilize blocking and parrying solely. Yet, the value of the Masukan Kaki lies within it's direct and often more aggressive nature. Considering that aspect then, you would also need something more than Tangkis or blocking to respond to an attackers hands in order to maintain that aggressive nature. Especially if you intend to own the timing of the conflict.
The answer from my perspective was to look at what works and what makes the foot entries effective on any level and expand that to a similar methodology for hands. This was done by looking at the silat systems I was studying at the time as well as my own experience, boxing, kalis, Arnis, kuntao, and other martial arts.
From that a methodology was born called Masukan Tangan and ultimately the beginning of viewing things quite differently from a martial arts perspective. The Masukan Tangan were quite different than other martial arts that I had seen at the time because they did not rely on blocking for the hands but were based on angulation through the use of Ales to put yourself in a position to strike the vulnerable areas of an opponent in real time - without blocking. As a result, you can conceivably steal the attackers timing and rhythm as your own and cause them to move from offense to defense within the span of time of a single attack.
In addition, with the use of the Ales you can create the necessary power to create a blow of sufficient force to incapacitate temporarily through the evastion AND leave yourself in close proximity to the attacker with a superior angle in most cases.
