How many instruments are there to form the ensembles?

Six or more instruments
In most cases, a larger classical group is referred to as an orchestra of some type or a concert band. A small orchestra with fifteen to thirty members (violins, violas, four cellos, two or three double basses, and several woodwind or brass instruments) is called a chamber orchestra.

Because most artists loved the way that their men or women that they were to paint/sculpture just the way that they had when they sat and posed and they thought that it looked more i guess