No, it wouldn't be close to the same. But it would likely be either part of a chuck roll or part of a shoulder clod. Both cuts are large cuts that comprise various muscle groups. Each cut is often either further separated into smaller named roasts or, probably more often, simply cross-cut into smaller 'chuck roasts'. Both the roll and the clod run from ~14 pounds on the small side upwards to ~23 pounds each, depending on the size of the carcass.
Many retailers do in fact get both clods and rolls and cut them into roasts themselves--they just don't realize that that is what they are doing(!). One thing you can do is ask whether the 5-pound roast you mentioned arrived that way or was it part of a larger hunk of meat that was cut in the store. It's that larger hunk, uncut, that you seek. It will be the clod or the roll (both are smoked/cooked the same way). Quite often finding something is in how you phrase the question. Employees might not know what a chuck roll is (or a shoulder clod) because they aren't the ones who check in the meat when it arrives or, perhaps, remove it from its cryo.
I used to haul meat from packers all across the Mid-west to distribution centers all over the country, including Florida where I live. I knew what I was hauling (including chuck rolls and clods) because I had to check the product. I can't tell you how many times I had to tell a meat department employee to get me a cryo'd 'big hunk of chuck'--unopened, uncut, direct from the packing case--before I could get either a roll or clod, despite the fact that the cases and the cryo are stamped with the name of the cut. Go figure.
If you ask if that 5-pound roast is cut in house from a large hunk of chuck and it is, in fact, not, then that store is likely not getting rolls or clods shipped in. This is not all that common--or wasn't--but is possible.