Thanks for the question. You are alluding to the Granville Sharp rule. That rule says that when two nouns are joined by KAI, and the first is preceded by the article, they refer to the same person if:
1. both nouns are singular
2. both nouns are personal
3. both nouns are not proper names.
In Eph 4.11, the nouns are not singular. In no instance in the New Testament do plural nouns fit the rule; that is, there is no clear example in which plural nouns in the Granville Sharp construction refer to exactly the same group of people. For example, in Matt 3.7 "the Pharisees and Sadducees" are in this construction, but no Pharisee was also at the same time a Sadducee. In Acts 17.12 we read of "the women... and men"! When participles or adjectives are in the construction in the plural, the dynamics are different. Plural participles always refer to the same group, as far as I can tell; adjectives in the plural frequently do.
The practical ramifications of your question though are a bit different. When the construction is in the plural, three broad semantic notions are possible:
(1) one group overlaps with the other in some sense (either partial overlap for both or one is a subset of the other); (2) the two groups are completely distinct; (3) the two nouns refer to the same group. As I said, the last option is not likely for nouns, since there are no clear examples of such in the NT (and very few elsewhere). I believe that in Eph 4.11, we are dealing with the first semantic option: some kind of overlap. Without going into the detailed arguments for such (you can read my Ph.D. dissertation on the matter, if you're so inclined!), I believe that the first group (pastors) belongs to the second group (teachers). That is, all who have the gift of pastor also would have the gift of teacher. This does not mean that someone with the office of pastor has the gift of teacher necessarily, though presumably one had the office of pastor should also have the gift.
For more information on Greek grammar and the Granville Sharp rule: See the author's Greek Grammar Beyond the Basics