People really dont bother to mention their roles when applying. Its true that we should not mention the word 'Director' in the job title For example Director Sales, Director Marketing.... Its not sensible in relation to providing services to your client. Director mostly 'directs' his own company's subordinates about company matters. Director has nothing to do being directly involved in providing services to the client. This is the reason HO advised to mention your role other than to be a Director of your company. It is better to say yourself 'Sales Manager' rather than 'Sales Director'.
Sales Manager sounds like you are involved in activities yourself.
Sales Director sounds like you are at higher post and define your company's policies for your Sales Managers about Sales' activities.
And yes you may find Sales Director in Appendix J and be satisfied that you find the exact title in the required list BUT remember that appendix J is not only for T1 Entrepreneur. It is actually 'Codes of practice for Tier 2 sponsors, Tier 5 sponsors and employers of work permit holders'. And HO specifically advised that its the duty of applicant to find suitable role for him/her depending on the duties. Therefore even if your title exists in appendix j but not 'Sensible', you could be in trouble.
I have learnt this after mistakes