Fair enough if you started with the assumption that everyone of...

Fair enough if you started with the assumption that everyone of these "holders of pretty good sized parcels of SOI (100k+ shares)" would need convincing to vote for the merger and 3% would end up convinced . But after 3 years of share price going sideways and some holders in red even before the merger was announced some holders would be ready to get out or try something different like a merger. Last year I was one of these holders , after 2.5 years of holding was lucky enough to bail out with the entire holding in a single day and with a little bit of profit thanks to the Tata MOU ann. It would be reasonable to suggest there are other 100k+ holders that have been trapped by low prices and low daily volume that would not need any convincing to vote for a merger and opportunity to see some decent profits that a merger would likely bring.
Anyway I would expect the TMT board already had the numbers in the bag before the announcement was announced to avoid ending up with egg on their face and forced to resigned if the merger was rejected but as you said it will be interesting to see the final results.
At this stage my guess is that less then 5% of SOI will vote against the merger.
Maybe someone should start a poll on the results of the vote.