This topic is a sensitive one. There are people who do not believe in drilling techniques (Kit Dale for instance) and there are people who drill endlessly in order to sharpen their technique , drilling being in favor of sparring.
When analysing this topic first we must remember that every person is unique. In our case, people don’t all learn the same. There are people who can learn very fast just by watching a technique, there are people who can just play it out in their minds over and over and learn it, there are people who have to feel the technique being done on themselves in order to learn it and also there are people who need some or all of the above.
Roger Gracie says that you should drill the move until you get the mechanics but then you should do more compliant resistance drilling.
So what is compliant resistance?
This is a phrase used by my professor to describe how a good training partner should behave whilst drilling a new technique. Applying only enough resistance for the move to maintain its structure from start to finish. Positional sparring is a key part of technique development but this is something entirely different.
Trying to drill a new technique while your partner is as limp as spaghetti is to be fair as awful as drilling with a training partner who thinks its OK to physically resist while you are trying to learn a new technique. The latter tho i think is one that takes a bit more effort to deal with. Left unchecked it will spread as people often get resentful and will only give the compliance they receive leaving a pretty poor environment in which to develop new skills .
Here is Roger explaining in detail: