Hi again,
I would recommend what you do is to breed your guppies in a separate tank altogether. House male and female guppies in a tank set up most conducively for them and provide some water plants etc. That would ensure the best breeding outcome.
You can then also control how many guppies and whether males or females, be placed in your axie tank. I recommend that you put in guppies of a single sex each time. If there are male and female guppies in the main tank, and an elusive pair evades being captured, they can breed in the tank. The downsides to this is that some guppies are prolific breeders and there is a chance that their breeding rate surpass their being eaten rate. This can cause overstocking in the tank, leading to water parameter problems.
How many guppies going into the axie tank depends on the size of the tank as well. For a start, i would go for around 3-5 guppies.
Cheers