I strongly urge a test where one of the options is one along the lines of scenario A, above - one that doesn't mislead uploaders or push uploaders to be dishonest. Test one that solicits enough information to be able to tell if uploads are free content in situations such as the three I mention in this comment.

The language "cross-wiki upload from xx.wiki" confused INeverCry. What language would be less confusing, INeverCry?

I agree when Whatamidoing-WMF says, New uploaders have approximately the same level of problems no matter which tool they use." But I disagree when W then says, "Changing the tool isn't going to solve this problem."
The bigger problem is this:
If you're failing to not make it unreasonably difficult for people to upload content and properly indicate why it's free when it is free then your definitions of good and bad are bogus and you have a GIGO (Garbage In, Garbage Out) problem with your assumptions and metrics.
It is unreasonably difficult for people to upload content and properly indicate why it's free: This tool only handles ONE type of free content. The Upload Wizard fails to properly handle some very common cases of free content. Until that is fixed, you are shooting yourselves in the foot.
Think about whether you need to make fixes like my implemented suggestions found at https://en.wikipedia.org/wiki/Wikipedia_talk:File_Upload_Wizard/Archive_4#3_proposed_edits_from_Elvey
See https://commons.wikimedia.org/wiki/Commons:Upload_Wizard_feedback/Archive/2014/10#Not_helpful for an example instance of a common case that the Upload Wizard fucks up. But if you say this is about fixing the new tool, not fixing the Upload Wizard then I say, in case it wasn't clear from what I've already said (it should be, if you read closely), that it IS about the Upload Wizard because our metrics for defining whether this new tool is better than the Upload Wizard are broken if we can't tell what's good or bad because we aren't even asking the uploaders using the Upload Wizard for enough information to be able to tell if their uploads are free content, which is what we *should* mean when we say good or bad.