Dividing Megillat Esther Among Readers

Question: Is it proper to divide the reading of Megillat Esther among multiple baalei kri’ah?
Answer: It depends what you mean by "proper," as we will explain.
The gemara’s (Megilla 21a-b) discussion of multiple ba’alei kri’ah refers to their reading at the same time, which is valid (Shulchan Aruch, Orach Chayim 290:2) although rarely done. The Magen Avraham (292:2) is the first major posek to discuss dividing the Megilla by sections, presenting it as a ba’al korei losing his voice in the middle. As the question is not discussed in the gemara or Rishonim, early Acharonim compare it to parallel areas of halacha. The Magen Avraham compares it to one who had to stop in the middle of haftara reading, where the replacement must return to the beginning (Shulchan Aruch, OC 284:5) and repeat the beracha (Magen Avraham 284:4). He says that while for Megillat Esther too the second ba’al korei returns to the beginning, he does not recite the beracha again because the first ba’al korei’s beracha was said for everybody, as we find regarding a switch in shofar blowing (Shulchan Aruch, OC 585:3). Indeed, regarding the beracha, the Rama (OC 692:2) says that one is allowed to make the beracha on Megilla reading for the reading of another.
The great majority of Acharonim say that the second reader does not need to return to the beginning of Megillat Esther. The Eliya Rabba (692:3) and Shvut Yaakov (I:42) agree with the comparison to shofar blowing but apply it the whole way. Just as regarding shofar, the first person’s blasts do not need to be repeated (Shulchan Aruch, OC 583:40), so too the p’sukim of the Megilla do not need repeating. The reason Torah reading needs to be repeated (Yerushalmi, Berachot 5:3) is that the whole reading needs to be linked to the opening and ending berachot. This makes it a problem when the first one made only the opening beracha and the second one only the concluding beracha (see Tur, OC 140). The Eliya Rabba says that Megillat Esther is different in that the ending beracha is not strictly related to the reading and in that the aliya for Torah reading is made by the oleh for the oleh, whereas the beracha for Megillat Esther is on behalf of everyone. Therefore, anyone can continue Megillat Esther where the first left off based on his beracha. The Shvut Yaakov says that the first reason is not universally accepted, but agrees with the second one.
It seems that according to the Magen Avraham, it is a major problem to break up the Megilla reading (Mikraei Kodesh (Harari) 7:(91) says otherwise in the name of Rav M. Eliyahu). According to the others, who rule you do not need to repeat, is it proper to divide the reading l’chatchila? Remember that the poskim describe the situation of a ba’al korei losing his voice, which may indicate that otherwise we would not allow the division. The alternative explanation is that it was just not common practice, but no halacha precludes the division even l’chatchila. The Shvut Yaakov and others who cite him prominently (including Shaarei Teshuva 692:2 and Kaf Hachayim 692:11) say that we do not go back to the beginning due to tircha d’tzibbura, but if the community does not care or only a few psukim were read, we would return to the beginning. Thus, it sounds like most poskim do not like the set-up l’chatchila.
Thus, I submit that a "purist" minyan would not agree to divide the Megilla reading. In addition to deference to the Magen Avraham and others, it is probably also more kavod for the mitzva to have one person do it. Due to the mitzva’s prominence, it also makes sense to have the best available ba’al korei do the whole thing. However, not all situations lend themselves to purist approaches. These include places where it is difficult for anyone to learn the whole Megilla well and communities in which the importance of involving as many people (especially, young ones) as possible is part of the shul’s DNA. This is a local rabbi’s call. (Since the ten-chapter breakup is non -Jewish, it is distasteful at best to break it up exactly in that way).