No offense taken.
I'm not following your teaocon and McConnell line of reasoning. Rand, Cruz, and Lee have all three staked out their own paths, mostly agreeing, a few times disagreeing. Over time, I recall Cruz especially voting for more spending where Rand didn't.
I also seem to recall Cruz and Lee going scorched earth regarding Obamacare, and Rand played it more strategically within the realm of the possible in the senate - maybe this caused a ripple.
Most recently, Cruz got zero support trying to enact legislation in the senate - something that has never happened, and Rand let everyone know Cruz was done for there. Seems like a good reason to distance oneself.
All that said, I don't think it's as complex as this with voters right now. If you look at Cruz and Rand in the polls, there within each others margin of error. Other factors are at play, mostly newness, ear tickling, and lack of depth, affecting the polls right now.