Spreading your bets makes the most sense with a scene as flaky as this one. Two alts is not diversifying. That reduces your chance of earning as you're only exposed to two when other may be exploding. XRP is slowly being exposed as junkier than ever. Nano has shat the bed quite stunningly compared to some others, but they've all been stunning.

Like I said it depends on the fees. If they're too high buying and withdrawing multiple coins then it's not a goer.