What is the test for determining that a common law marriage contract between two equal strength spouses does not need to be subject to the same rules as a commercial contract?

The Wife refers to Rick v. Brandsema, 2009 SCC 10. That case confirmed that separation agreements should not be subject to the same rules as those applicable to commercial contracts negotiated between two parties of equal strength, because of the uniqueness of the negotiating environment, which is “on the fault line of one of the most emotionally charged junctures of their relationship - when it unravels” (at para. 40). The case confirmed that the court must be sensitive to the “social and socio-economic realities” that shape parties’ roles in spousal relationships and have the potential to negatively impact settlement negotiations upon marriage breakdown (at para. 41). Judicial intervention would be justified where agreements were found to be procedurally and substantively flawed. However, the court must respect the parties’ right to decide for themselves what constitutes for them mutually equitable sharing.