Your information is in correct. There is no requirement of having worked for a certain period to apply for LMIA. Basically if you have an employer willing to apply for LMIA and they can prove it i.e. the job specification is such that its not easy to find Canadians and that your spouse possess those skills, then you can apply for LMIA and then work permit / PR application based upon that.
For people with the right skills, employers file for LMIA while they are outside of Canada and bring them here on work permits or PR, based upon LMIA.
If the intent of applying for LMIA is to get PR, even then it is separate from PR.
LMIA if approved, gets your spouse additional 600 points. That will get them an invite to apply for PR, provided they meet the minimum criteria for ONE of federal PR programs i.e. FSW, CEC or PNP.
It is CEC which requires one year of full time Canadian work experience.
FSW requires one year of experience in your NOC ANY WHERE in the world, if you provide appropriate experience letters and have matching educational qualifications.