Roland Warzecha has quite a bit to say on the subject. You should consider looking through his website and YouTube channel.*
His research and experimentation has concluded that the bind is the foundational principle to sword and buckler combat theory.
*Disclosure: I am in no way connected to Roland Warzecha, or his HEMA school.
Edit: The way that a bind is initiated is entirely dependent on the combatants and the circumstances. Two fighters used to fighting from the bind may both approach to measure and immediately initiate a blade bind. However, when fighting against an opponent who is not skilled in use of the bind and/or prefers a more percussive/aggressive style, one may need to initiate a bind from an offensive (e.g. a covering blow) or defensive (e.g. parry or envelopment) technique. Once the bind is initiated, control of the opponents weapon can in fact be more tactically important than covering the centre (YMMV).