Standardising a score of values


I am working on developing on a standardised score from a number of scores.

The values will be ranging from large to small of each score and I am trying to develop a way of proportionally measuring different data sets. I have something at the moment which is:

(x1/largest x in dataset1) x100

(y1/largest y in dataset1) x100

(z1/largest z in dataset1) x100

[and so on.. and then I find the mean of the answers.]

I then compare the mean to the another mean but from a different data set (dataset2). Is this standardised? And an accurate way of measuring these scores? I've considered doing z-score scaling. I am not very maths competent so apologies if I have created any confusion.

Please do let me know if you have any questions.

Thank you,