You wouldn't really be maximizing your chances (also I don't know what the implications are about having two profiles for 'one' applicant in the pool at the same time - CIC may not like it, but I don't know).
Your completed express entry profiles will each be given a CRS (Comprehensive Ranking System) Scores, and it's these scores that determine if you get an ITA (Invitation to Apply). CIC does 'draws' once or twice a month, where they specify a minimum CRS score cut-off. Any applicant with a score at or above this cut-off gets an ITA. So, even if you decide to enter two profiles into the pool, only the profile with the higher CRS Score really matters. Assuming one or both meet the minimum cut-off, either the 'higher-scored' profile will get an ITA, or both will get an ITA. But the lower-scoring one will never get an ITA over the higher scoring one... I don't know how well I'm explaining myself here but, bottom line, it really doesn't make sense (creating both profiles is just a waste of time).
From an ethical standpoint, using your stated method could possibly be at another applicant's expense (if applicants with higher scores had multiple profiles in the pool, then applicants with slightly lower scores would be 'edged out' of draws since draws only accept a specific number of people, and CIC wouldn't be able to tell that those 'selected' profiles are actually duplicates).
Do yourself (and other applicants) a favor, and only submit one profile. Use the CRS calculation tool (see link below) and find out which primary applicant will result in a higher CRS Score, and then just go with that decision...
http://www.cic.gc.ca/english/immigrate/skilled/crs-tool.asp