In the end, it's the player that has to choose the club and how to hit it .
Many of us choose the putter scale so we don't often use more than 20% of a full stroke, and mostly use 15% or less of a.full stroke. The idea is to shorten the meter run length and improve dingability..
For a 25 foot putt I might choose to use 25% of the 100 foot scale. For a 25 foot putt on faster greens, I'm likely to use the 150 scale and a 155 stroke which would be equivalent to a 22.5 foot putt, but will go 25 feet or so on the faster green.
No doubt, adjustments also have to be made for uphill and downhill putts.