Understanding concord

Make your rules precise and consistent. If you have a tendency to forget, write them down and place it where everyone in the family can see them.

The above paragraph is taken from a newspaper article. Is there anything wrong with the paragraph?

If you find nothing wrong, you need to know what concord is.

Concord is agreement between words in case, person, gender or number.

Now, the paragraph is reproduced below with numbers of words shown in brackets that are not in concord:-

Make your rules (plural) precise and consistent. If you have a tendency to forget, write them (plural) down and place it (singular) where everyone in the family can see them (plural). These words [them (plural), it (singular) and them (plural)] are pronouns and they are all representing/referring to the same 'rules (plural)'.

Concord, therefore, requires the paragraph to be recast as - "Make your rules precise and consistent. If you have a tendency to forget, write them down and place them where everyone in the family can see them." Actually, this last them is redundant and can be conveniently deleted without affecting the meaning/sense of the paragraph.