Add several feeds into an array
It looks a bit awkward, but to append items to an array you have to use Twig's merge filter, merging the feeds_array with itself for each new item. Here's how I'd do it if you need different logic for each feed:

{% set feeds_array = [] %}

{% for node in craft.feedme.feed(my_rssfeed) %}
    {% set feeds_array = feeds_array|merge([{ title: node.title }]) %}
{% endfor %}

{% for node in craft.feedme.feed(my_otherfeed) %}
    {% set feeds_array = feeds_array|merge([{ title: node.whateverField }]) %}
{% endfor %}

{% for post in feeds_array %}
    {{ post }}
{% endfor %}