Rouge One screenwriter Gary Whitta said:
I thought having Evazan and Walrus Man was a little too much.
I very much agree.
And about the “transmissions vs. Data Tapes” debate, it make sense to me that both happened. They beamed the plans via “several transmissions” and then the crew downloaded that data onto tapes. Maybe I’m missing something (I’ve only seen R1 once), but I don’t see any problems there.