Sounds like you could use pairwise:

my @a1 = (
    ['a','b','c'],
    ['d','e','f'],
    ['g','h','i'] );
my @a2 = (
    ['j','k','l'],
    ['m','n','o','p'],
    ['q','r'] );

use List::MoreUtils q(pairwise);
use Data::Dumper;

my @merged = pairwise {[ @$a, @$b ]} @a1, @a2;

print Dumper \@merged;
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