The so-called Jianghuai dialect is actually a Western dialect. The earliest spoken language in Huaixi is ancient Chu language. Chu was in Fuyang, Anhui in 12, followed by Shouchun in Huaixi in 19. At this stage, Huaixi people controlled the vast Jiangnan area and developed it, such as Shanghai. In other words, there were Anhui people in Jiangnan in the late Chu State. In fact, the official language of the Ming Dynasty is not Huaidongfang dialect in Jiangsu province, but Huaixihua dialect in central Anhui province. Huaixihua dialect is relatively easy to understand because of its curly tongue and nasal sound, but it is voiced. Compared with Huaixihua dialect, Huaidongfang dialect retains more traces of ancient Chinese and is more difficult to understand.
Outsiders sound like Wu dialect, that's their ability to distinguish sounds. Jianghuai Mandarin is very different from modern Wu dialect, but it has its origin. Jianghuai Mandarin was based on the ancient Wu dialect and later merged with Mandarin. Modern Wu dialect developed from the ancient Wu dialect itself. I'm from Lianshui, Huai 'an, and I think at least one third of foreigners can understand our dialect, just like we can understand a little dialect around Suqian Lianyungang Yancheng Xuzhou. But this has nothing to do with Wu dialect. Wu dialect circle is in Jiangnan, and many words are difficult to understand. Even locals, different local dialects are sometimes difficult to understand, so it is normal for northerners not to understand.