When the file gets to the visa office, yes, not at CPC-M. At CPC-M, you just have to wait your turn to be approved as a sponsor, you won't be passed ahead of others. Spouses and dependent children are the same stream in Family Class, in any case.
Children are prioritised by visa offices because they are minors (usually) and obviously need to be reunited with their parents to have proper care and guidance, so their best interests are served by their cases being processed quickly (attention to the best interests of the child is codified in Immigration and other Canadian legislation). Secondly, children under 18 will have almost no background or criminality to be investigated (usually) so their cases may be cleared much faster than a spouse's, so it makes sense to deal with them first.