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I believe Google have started considering sub domain as part of the main domain so multiple links of the same domain in the search results is hardly a chance and if you are seeing it, it’s a matter of time when this will change. If you 301 redirect two pages the preferred version will get the links and authority of almost two pages but I am not sure how Google will take it when it comes to rankings as there are 200+ other signals that Google uses when ranking a website in search engines. Ideally what you should be doing is considering your audience in mind before taking any action. If consolidating two pages as one will make a positive difference to audience, I believe you should go for it as audience comes first and search engine comes 2^nd. Hope this helps!