Clusters of galaxies come in all angular ~sizes~ dependent mostly or range. There are plenty of Abell Clusters that are nicely captured in a 1o field using a largish scope. For a 3.5o field the selection is more limited... to just a few. But if you enjoy good dark skies... can point the telescope in any random direction and have myriad detectable galaxies in the field. e.g. Here's a picture I took with my old 12-inch scope onto film back in the mid 1980's. I was intending to only image NGC 7331 and Stephan's little group of five there... but you can see other generally-ignored galaxies sprinkled all over the place. I got into the habit of examining every deep sky shot for galaxies... and always finding them. To the point where I conclude that it would be challenging to shoot a random pointing and not find galaxies!
Worth considering: >>> Instead of always shooting the same few dozen targets that all the other guys are forever imaging, pick something that is ignored... or even a random field that shows nothing notable in the atlases. I guarantee you will not be disappointed!
Q: "Would you like to see my picture of Niagara Falls?"
A: "Ummm... No."
Q: "Would you like to see Chris's picture of a substantial water fall that we stumbled across while hiking along Reynold's gull last week?"
A: "Really, I never knew... Yes!" Tom