[Advaita-l] Three bramhacharis in one home

[N R, Chakradhar (Chakradhar)]

Is there any restrictions in any Dharma Shastra's (Smritis) or Sutras about NOT doing UPANAYANAM for the third male child if the elder brother is not married because there will be three brahmacharis in a single home?
The reason I could gather was that marriages to some of those male children will not happen. The reason is not very convincing.

What is the alternative suggested in such cases?
Can the elite members of the forum please share their views on the above topic?

Thanks and Regards,
Chakra