They stood chatting together as easily and naturally as could be
书上说比较分句中省略了主语或也可看作由as/than充当了比较分句的主语。
1）这句话该如何怎么翻译和理解？
2）比较分句中如果看作省略了主语或也可看作由as/than充当了比较分句的主语的话，那么主语是不是就是They呢？
后面的比较分句其实是不是这样的(假设可以补全的话，我了解相同项必须省略，这里补全只是假设，便于理解）：
They stood chatting together as easily and naturally as (省略THEY或看作as=THEY) could be (easily and naturally)
请问我补全的对吗？
3）They stood chatting together as easily and naturally as (省略THEY或看作as=THEY) could be (easily and naturally)
如何怎么翻译后面假设补全的： as (省略THEY或看作as=THEY) could be (easily and naturally) ？好难理解这里的意思！
麻烦能针对这个句子的后面的比较分句，多讲解一下句意，我感到好难理解。
谢谢！