I have not fully read all of the requirements so where does it say that in the requirements?
Taken from Appendix FM-SE - Family members - specified evidence
http://www.ukba.homeoffice.gov.uk/policyandlaw/immigrationlaw/immigrationrules/appendix-fmse/
2. In respect of salaried employment in the UK, all of the following evidence must be provided:
(b) The P60 for the relevant period or periods of employment relied upon (if issued).
(c) Wage slips covering:
(i) a period of 6 months prior to the date of application if the applicant has been employed by their current employer for at least 6 months; or
(ii) any period of salaried employment in the period of 12 months prior to the date of application if the applicant has been employed by their current employer for less than 6 months.
(d) A letter from the employer(s) who issued the wage slips at paragraph 2(c) confirming:
(i) the person's employment and gross annual salary;
(ii) the length of their employment;
(iii) the period over which they have been or were paid the level of salary relied upon in the application; and
(iv) the type of employment (permanent, fixed-term contract or agency).
(e) A signed contract of employment for employment currently held.
(f) Monthly personal bank statements corresponding to the same period(s) as the wage slips at paragraph 2(c), showing that the salary has been paid into an account in the name of the person or in the name of the person and their partner jointly.
As long as you supply the evidence above, backed up with you letter of support detailing you salary arrangements, then I cannot see any grounds for refusal.