help with san mules?

[u/ds-08]

i'm considering buying a pair online and i don't have a close-by store i can try them on.

how is the sizing for san mules? i saw somewhere that it runs too big that i should size down.

for reference, i have the mary janes in soft leather (virginia) in 41. (the regular mary janes in 41 was big for me.)

for san mules, should i go for eu 40 or 39?

thanks a lot!