Is this a valid routing using Skymiles for 1 award ticket?

NRT-MEX-LAP
LAP-MEX-GRU-ASU
IGU-GRU-MEX-NRT

So basically it's 1 stopover + open jaw (on AM & G3). But I'll be routing through MEX 3 times, and not sure if it's allowed. Or maybe I should book 2 tickets like the following?

ticket (1)
NRT-MEX: stopover
MEX-GRU-ASU: destination/open jaw
IGU-GRU-MEX-NRT

ticket (2)
MEX-LAP
LAP-MEX