The way that the People costs are defined in the Shorter Schedule of Cost Components is so vague and contractually imprecise, in my opinion, as to be almost worthless. As a non-accountant, I might be able to come up with a reasonable way of expanding on what "amounts paid by the Contractor" to people "including those for meeting the requirements of the law and pension provision" means in practice and I am sure you could to - it would just be that yours and my way would be different !
The Guidance Notes do not offer much help at all, but do say "The intention is that amounts paid in the Shorter SCC would cover all the specific items listed in the full SCC." In which case, the obvious response, to me, is 'why not repeat what is in the full SCC in the Shorter SCC ?'
As a practical means of assessing people, I therefore suggest you use the the build up for People in the full SCC. The alternative is to get the Contractor to tender rates for people (which you assess / negotiate over prior to signing the contract when there is competitive tension) and these are then used instead as per clause 52.1