You express yourself well, and it's clear how much effort you have invested in sharing your ideas. It is enjoyable to read a thoughtfully articulated perspective. However, I find myself questioning some of your conclusions. Allow me to present my interpretation of this vratham along with other viewpoints.
Sumangali Vratham is a customary ritual conducted as a religious ceremony by married women to seek blessings for the health, longevity, and prosperity of their families, especially for the long life of their husbands and the marital success of young girls in the home. This belief appears to be rooted in the principles of a patriarchal society, where a woman is considered complete only when married. As a child, her father looks after her, and later, her husband takes on that role. If she outlives her husband, it reflects poorly on society that often mistreats widows, while widowers are generally treated well.
You are correct that nearly all so-called Vedic rituals are intended for married individuals. However, it is important to note that the Vedic texts do not specify who the kartha, or doer of the ritual, is. The Vedas, taken as a whole, assert in the relevant Upanishad sections that the sādhaka is NOT the kartha or doer. Nevertheless, the Mimamsakas, who developed the science of sentence interpretation, used presumptive logic to argue that a kartha must be implied, as karma cannot exist without a kartha. The Smruthis provide many specifications over time. Ultimately, all that occurs in rituals is based on smruthi and purana stories, supplemented by local traditions developed within families. As you rightly pointed out, Sumangali Vratham is primarily a locally based traditional ritual.
I am uncertain about many of the claims regarding veda rakshanam aspects. Shraddham is performed as a Naimitthika karma, with Brahmanas invited to partake, symbolically representing Pitrus. It is not conducted for the purpose of veda rakshanam. Those Brahmanas who partake in the ritual and have food are generally looked down upon by the Vadhyar who performs the ritual in these days
Typically, an odd number of sumangalis (such as 5, 7, 9, etc.) are invited for a sumangali vratham, though I am unsure of the reasoning behind this. A young girl (pre-puberty) is also invited and regarded as a symbolic sumangali.
Sumangali Vratham serves to honour female ancestors and seek their blessings. It celebrates feminine energy (shakti) and the sanctity of family life. It can also be viewed as a form of ancestor worship from a matrilineal perspective.
The precise origin of this practice is unclear and is not documented in any classical Hindu scriptures. However, it is thought to have developed as part of the Smartha and Vaishnavite Brahmin traditions, particularly within Tamil and Telugu households. It likely emerged as a socio-religious practice as families began to highlight the importance of marriage and the role of women in upholding dharma and household prosperity.
This ritual combines pitru tarpanam (ancestral worship) with the reverence of married women, reflecting the traditional South Indian belief that the blessings of women who passed away as sumangalis are particularly potent.
