Spouse Visa- Adequate Maintenance and Accommodation

Hello, my husband is about to change the route of his visa from 10 year route to 5 year route. We have been told that the easiest way to apply is under the 'adequate maintenance and accommodation' method rather than having to prove our 18600 income and have to be under the same employer for 6 months minimum (which my partner is not yet).

I am in receipt of PIP (Personal Independence Payment) and so qualify.

I am confused about how to calculate weekly income from my work. As i am paid monthly, i have 6 payslips now, which amount to 21 weeks and 4 days.
So is the weekly mean average calcuated by:
-- total income earned divided by 21.51.. (weeks)
OR
-- total income earned divided by 26 (52 weeks in year/2)

I have looked on the link below from HO, but it only gives examples of 4 weekly income rather than monthly income. https://assets.publishing.service.gov.u ... nnex_F.pdf

I am planning to apply asap, so any help or advice would be much appreciated.

It would be great if someone could also confirm that we do not need to show 6 months payslips for the income to qualify?
So my husband has been working for 18 weeks in his current job, and so would it be acceptable to include his income too by dividing his total income by 18 to work out weekly average, which would also be included in the net income?

Our total net income (A) is: £137.72 + £320.42 + £108.25 = £566.39
---my wages from 6 months payslips (£2970.90 divided by the weeks worked in this time) =£137.72
---my husbands wages from 18 weeks (£5767.63 divided by 18) =£320.42
---PIP (paid 4 weekly of £433, divided by 4) =£108.25
Are all of these permissable?

which is more than income support of £114.85
...so we must qualify?