Child dependent visa - travelling with one parent

Hi, I need some advise please.

I am based in India currently and I got a job offer from UK company offering COS. I am in the process of applying visa for myself and my son (5 years old).

My husband who is also based in India cannot travel with us right now. His company will transfer him to UK at a later date but there is no official confirmation of this. So he wants to wait and not quit the job right now.

Also, my husband has elderly parents and they need his support as he is the only child so it will take sometime for him to make some arrangements.

We will get consent letter notarised, but should we provide any additional documentation as father won't be traveling with child at the same time?

Thanks

See also Why can’t my children join me in the UK?