
Tiger R. answered 11/26/19
Self-Taught in Excel and Full Time Data Manager since 2013
You could certainly use HLOOKUP or VLOOKUP approaches to solve a challenge like this, but in the long run, it won't be particularly stable or sustainable, especially if anyone else ever accesses or edits these files.
A longer term solution would be to use PowerQuery in Excel and identify a common key (a column that holds a data point that all three data sets will have in common) to merge data across tables regardless of new additions. This also works well if you perform the same or similar queries across different data sets.
For the challenge you name of the account names being in different columns, you can also use PowerQuery to create an array and then find the position/column number of the value in question.
https://docs.microsoft.com/en-us/powerquery-m/list-positionof
These are just some thoughts to get started with!