I will humour you.
They came to the other side of the sea, into the country of the Gerasenes. 2 When He got out of the boat, immediately a man from the tombs with an unclean spirit met Him,
When He came to the other side into the country of the Gadarenes, two men who were demon-possessed met Him as they were coming out of the tombs. They were so extremely violent that no one could pass by that way.
Then they sailed to the country of the Gerasenes, which is opposite Galilee. 27 And when He came out onto the land, He was met by a man from the city who was possessed with demons;
Now the standard reply is that they are two towns in the same general region so there is no contradiction. However, this is silly. The contradiction is plain. All accounts use the time connective 'when' which implies in all cases immediacy. When this happened, this happened. Thus, no traveling can be done. Looking at any map, the use of Gerasa is nonsensical (at least 12 miles from Gadara - ie further from the lake) - it is inland and too far for the sense to be made. Here is the hilariously bad bad harmonisation from Barne's noted on the bible:
"Country of the Gergesenes - Mark Mar 5:1 says that he came into the country of the "Gadarenes." This difference is only apparent.
"Gadara" was a city not far from the Lake Gennesareth, one of the ten cities that were called "Decapolis." See the notes at Matthew 4:25. "Gergesa" was a city about 12 miles to the southeast of Gadara, and about 20 miles to the east of the Jordan. There is no contradiction, therefore, in the evangelists. He came into the region in which the two cities were situated, and one evangelist mentioned one, and the other another. It shows that the writers had not agreed to impose on the world; for if they had, they would have mentioned the same city; and it shows. also, they were familiar with the country. No men would have written in this manner but those who were acquainted with the facts. Impostors do not mention places or homes if they can avoid it."
So bad it's funny.
Then there is the problem that Matthew clearly states two demons, not one.
You will have an answer, no doubt. It's just that to think it is plausible takes some wild gerrymandering.
Yes, indeed there are answers that don't require punting to the conclusion that the Bible is contradicting itself. Pearce recognizes that the passages are referring to two cities: Gerasa and Gadara. What I don't get why he think Mark and Luke think Jesus went to one city and that Matthew says that he went to the other? The texts do not say that it. They say that he went to the region containing those cities. The miracle that happened did not occur in a city or town. Pigs weren't kept in towns, as far as I can tell. The pigs are also an important point because it shows that the area was primarily populated by Gentiles - which is what Archaeology and extra Biblical sources tells us. Had the people been Jews, they would have neither cared about loosing a heard of pigs nor owned pigs.
As for the number of men Jesus met and healed. Mark and Luke definitely says that there was one one guy while Matthew says there were two. The thing is how is this a contradiction? A contradiction would be if Mark and Luke had said that there was only one man. They don't. Each of the Gospel contains details that are not in the others. But none of those details contradicts the details in the others. If I tell you that Jack and Jill went to the mall and bought a DVD, but I tell another person that Jill went to Walmart and bought a DVD, did I contradict myself? Nope. I just didn't give the same detail. A contradiction would be if the mall did not have a Walmart. You don't have such a thing in this case. We know that Jesus went to an area containing two cities, Gerasa and Gadara, and while he was there he cast demons out of two men that met Him as he came ashore and they knew who Jesus is. The demons drove some pigs mad and they drove themselves off a cliff into the Lake and drowned. No need to bring up phantom contradictions. If Pearce or anyone disagrees, I'd love to know what is so bad or false about understanding the text this way.