Not enough coffee yet, but by 'Merge' do you mean inserting alternates?

i.e.

ary1 = {1,3,5,7,9,11}
ary2 = {1,2,3,4}

aryOut = {1,1,3,2,5,3,7,4,9,11}

or

aryOut = {1,3,5,7,9,11,1,2,3,4}