Thanks to a post on /r/badhistory I ended up watching the 1970 film Waterloo last night and I was reminded of a Staff Ride I attended some years ago. during a tour of Waterloo, the guide claimed that Wellington's choice of the ridge at Mont St Jean for a defensive position was based on Marlborough's assessment, 100 years earlier, that it was the ideal position to defend Brussels from the south.
In the film Wellington is portrayed as having surveyed the ground himself in 1814, but was he inspired by Marlborough?
I asked this of well read friend of mine who explained it to me paraphrased as:
Belgium was studied by most generals during the time period as it was one of the primary focal points of combat for centuries in Europe.
Plus, it is no secret that Wellington did indeed study Marlborough, as most generals should have and did, and it is very likely his campaigns were of guidance.
However it is most likely that it was Wellington himself and perhaps his DQMG William De Lancey who made the final judgement call on the place to offer battle.