Hey Plantyman8,
in my experience with Anadenanthera, if they rot or die while I'm sprouting them in winter, waiting til April-May(spring/warm) is the best option.
Then you can start them in a humidity chamber by a windowsill and they'll sprout right up and you can remove the dome after 3-4 weeks or less.
Feel free to express your depleting seed concerns via the "Request" section, likely someone will assist your needs.
Are you making sure to scarify the seeds? They need to have near boiling water poured over them and they can sit for 1-2 days.
Ensure your soil is moderately-well drained with pumice/perlite/sand etc. and after you lay down the seed, only sprinkle a bit of compost/worm castings over it. Oversaturating legume seeds with rich compost generally leads to rot when I have done that. And make sure you allow the pot to breathe every now and then by unmasking the humidity cover. A good misting every now and again helps as well, be certain the soil does not dry out during the seedling stage.
Once these guys take off, they grow so fast!