is it normal dupeguru indicate 100% match when file don't have same size with the reference ?

[iostrym]

with scan type : filename
application mode : standart

it is very quick to look for dupe in this mode. only the filename is checked.

but I think I could focus on match percentage to look fo exact dupe : identical name + identical size give me a good confidence.

but I discover that the tool put in the list some file with different sizes. (less than 1%) it is dangerous because I could have deleted all these whereas they are not dupplicate.

is it normal ? is there a mode as quick as this one that could help me not to remove file that have a size that is different from the reference ?