It is a general fact that every body has been paid according to value to society. In case of various Govt Organisations, Deptts., & Corporation an educated person join his / her post with a little on the job training. Hence replacement are easy.
But in case of armed forces and police we have long training courses to make new member fit and organised. the money spent on training is investment. Hence we must take care to pay salary to armed forces and police better then other govt offices. this is perhaps right way to justify importance for country.