To be eligible for FSW nomination, one must have at least one years experience in a nominated occupation. According to your post, you have more than that in two eligible occupations - 1111 and 0013. So that's not a problem. CIC checks whether you're eligible for nomination under one of the nominated occupations by cross-checking whether your experience, as stated by your employment reference letters, STRONGLY fits the duties performed description of the nominated occupation. I understand that you want to claim points for the occupation that you've worked the most number of years (1111). But, if the reference letter only matches 20 percent of the duties performed by a typical NOC 1111, you RISK REJECTION. On the other hand, if you nominate NOC 0013, you have a much higher chances of success as your experiences more strongly match that occupation.
I think the less riskier course of action for you is to nominate NOC 0013. BTW, according to the FSW spreadsheet there are 80 applicants in NOC 1111; in contrast, 0013 has only 20 entries.
Seems like you have better odds with 0013 in that aspect as well.