Teachability beats sophistication
A scheme that takes two years to learn is worthless in an environment where players may stay one or two. The successful programmes tend to run simpler structures executed to a high standard, because simplicity is what survives constant reintroduction. What looks conservative from the outside is often the only thing that can be installed in a preseason.
Defence travels better
Defensive principles — how to guard a screen, when to help, where to funnel drives — are largely effort and positioning, and they can be drilled into new personnel faster than offensive timing can. That is why so many programmes with stable reputations are known first for defence: it is the part of an identity that can be rebuilt annually.
Identity as recruitment
A clear system also filters who arrives. Players choose programmes partly on whether the style suits them, which means a distinctive identity partially self-selects the roster that can execute it. The system and the recruiting are not separate problems, which is easy to miss when discussing either alone.