When I run into these, I go back to "What am I trying to learn?"
In this case, I'd revisit how I'm going to measure what "Makes the most sense" and what is "easiest".
If you have the users self-rate (i.e. How easy was this on a scale from 1-5), you may run into users always thinking the last option was best/easiest ("recency bias") and users wanting to say what they think the researcher wants to hear.
If you're able to use something like Time on Task or Number of Taps, it might help bridge the Say->Do gap as you'll be measuring how long it actually takes them instead of how long they felt it took them. Often very different things. =)
Something else coming to mind is showing three separate groups of user testers only a single version of your design and compare stats between the three so you completely remove the "figuring out the other two" issue.
Once I worked with the team who handles the live website and had them target real users coming into the site. They were able to put a banner for certain visitors which linked to our User Test. We had to tread carefully as management people were rightly very wary of sending users into an area with an incomplete experience, but we were able to quickly get fast data from real people visiting the website (we were testing who would try to do something online through self-service instead of calling or emailing the company).
I always find it helpful to have someone outside my UX team do a "Dry run" of the test, as well as someone inside the UX team as they will likely be able to give really pointed feedback.
I hope some of this helps!
At the end of the day, you'll be learning something no matter what and the fact you're doing any User Testing is great news. Keep it up!