It is very inconvenient that the custom fields in Page Layout cannot be re-ordered. 

The only way is to remove the fields and re-create them; however, it is impractical. 

This would affect the reports and dashboards we are having.

Not able to re-order the field making the fields are shown in weird order....especially some fields were added at the later stage. The added fields may be related to other fields and should be located near to the related fields. Now, they are shown at the bottom.