People's names can be confused too. A few weeks ago I referred to the Legendre symbol as "Lagrange symbol" by mistake when talking to a colleague. Such things are inevitable however you name things; some words happen to have small Levenshulme-distances...
Particularly if the names are hard to pronounce or remember because of the cultural and language difference. Few French-speaking people would confuse Legendre ('the son-in-law') and Lagrange ('the barn').
Lagrange vs. Legendre is kinda really easy to mix up, since you have Legendre polynomials and Lagrange polynomials and both are important in numerical analysis...
