Re: Historical Places of the Subcontinent
Intereting post bao bihari. It makes me think was Sahaba e Rasool travelled to Sindh before Arab conquest in 712 AD (i.e. after 80 years after the death of Rasool Allah 
). We have Mazar of Abduallah Shah Ashabi in Makli graveyard, Thatta too.
The uploader of this video provided information that Hazrat Abdullah cam to Sindhduring Samaa Period in 10th Century AH i.e. a Milenium after the Prophet.
I’ve seen people claiming some foot sign in Laki Shah Saddar (near Sehwan Sharif) that they belonged to Hazrat Ali. Also there is a place Lahoot in Balochistan, which is treated as sacred place by Shia sect on the belief that Hazrat Ali visited and stayed there. If we see the historical perspective of these claims, they are just myths.
Coming to graves of Sahaba near Sukkur, that may be people who accompanied MBQ during his conqust of Arod ‘current day Rohri - the twin city of Sukkur’.