The size of Doulichion
The suitors from Doulichion alone almost come to those from Odysseus' islands put together. Therefore, Doulichion must have been almost the size of Odysseus islands, which amounts to some 1550 square kilometers. Based on the avarage amout of suitors Doulichion must be 1439 square kilometers.
There is no island that size amongst the Ionean islands. Doulichion can't be any of the islands nearby. So, Doulichion must either be far away (which isn't very likely since 52 suitors or wooers came from Doulichion) or Doulichion isn't an island. Doulichion must be part of the mainland!
By setting the surface of Doulichion at the same percentage of the amount of suitors, which is 48%, and assuming that Lefkada is ancient Ithaca, the comparison between suitors and the surface amount of the islands fit very well.
There is no island that size amongst the Ionean islands. Doulichion can't be any of the islands nearby. So, Doulichion must either be far away (which isn't very likely since 52 suitors or wooers came from Doulichion) or Doulichion isn't an island. Doulichion must be part of the mainland!
By setting the surface of Doulichion at the same percentage of the amount of suitors, which is 48%, and assuming that Lefkada is ancient Ithaca, the comparison between suitors and the surface amount of the islands fit very well.
Suitors
Surface
From Doulichion there are fifty-two choice youths, and six servants in attendance, From Samê there are twenty-four men, from Zakythos there are twenty youth of achaeans, and from Ithaca itself there are twelve, all best men,
Odyssey Book 16 line 237-241 Barry B Powell
Once Odysseus returns home, his son Telemachos tells him 108 suitors have arrived (men who wanted to marry Odysseus' wife Penelope):