Reactivity of anhydride vs aldehyde with nucleophile

It is known that order of reactivity of carbonyl derivatives towards nucleophiles follow the order as:



> 
> Acyl halide> acid anhydride>ester> amide> amide derivatives 
> 
> 
> 


(**Source**: "A Guidebook to Mechanism in Organic Chemistry" by Peter Sykes M.Sc., PhD., F.R.S.C., C.Chm. Fellow and Vice-Master, Christ’s College, Cambridge.)
(Here amide derivatives are NRR' only)


It is difficult to find out the order in books and online as well, if we also include aldehyde and ketones.


Well there is one such debated question on [Chemistry Stackexchange](https://chemistry.stackexchange.com/questions/14618/rationalising-the-order-of-reactivity-of-carbonyl-compounds-towards-nucleophiles), but the fact that anhydride is greater in reactivity than an aldehyde confused me as why is the acid anhydride's direct conjugation (even though if it's cross conjugation) less effective in stabilising the positive charge on carbonyl than the aldehydes hyperconjugation?


