Form may be of slighter consequence than substance....

[Silverobama]

Happy Holidays.

The following paragraph is from The Elements of Teaching by James M. Banner and Harold Cannon:

Standards range from minor ones (such as the appropriate form for written assignments) to major ones (such as how much a student must know about the reproductive systems of various kinds of animals in order to meet the requirements of a biology course.) No matter what their level of importance, expecting strict adherence to all standards --- the reasons for all of which should be openly explained --- is a mark of all good teaching. Form may be of slighter consequence than substance, but to yield in small matters makes it harder to maintain standards when they really count.

I have difficulties understanding the bold sentence. I rephrase it as:

Form may be matters less than substance, but to yield in small matters makes it harder to maintain standards when they really count.

My questions:

a) I wonder if "when they really count" means "when standards really matter" here.
b) I also want to know the connection between the first and the second sentence. Does "form" mean "small matters" here while "substance" refers to "standards"?

 

[Tarheel]

Of slighter substance - less important

Form - the way things are presented
Substance - what you know

 

[Silverobama]

Thanks a lot, Tarheel.

Could you please help me with my questions. I already know what "of slighter substance" means but I still don't know the answers to my questions.

 

[Tarheel]

If you give in on small things it's harder to hold your ground on big things (when it really matters).