The “one size fits all” approach to training is not good. Everyone is not alike, no matter how you slice it.
I have experimented with various levels of training frequency and volume over the years for myself and those I train. Work capacity varies from person to person.
Some people will thrive training only two or three days a week, others will stagnate on that schedule.
Some people can train five days straight and excel while others will be annihilated by that pace.
The most extreme case I have seen recently was a guy who served in the Bulgarian Special Forces. He trained twice a day, five days a week and played soccer on the weekends.
His work capacity was “through the roof”. The crazy thing was, he could handle it.
As a coach don’t try to hammer people into fitting your mold. Treat each person on an individual basis. That will help bring out their best.
You must know your people and program accordingly!
The Cave 
Good post Frank, I see a lot of trainers, especially new or less experienced trainers/coaches try to squeeze there own mold onto a client that is clearly not going to fit. Great advice.
Thank you, my friend! GOD bless!