Do you think that evaluating a firm (involved in investing and other financial transactions) on the basis of its prior investments is a good way of determining the overall success of the firm? It would be great to get your opinion, and perhaps suggestions of a better way of doing this.
No, I don't think there is anything wrong with the method you are mentioning but you will have to make sure that you do this in full, rather than just looking at the actual investments you should concentrate on the returns which came from those investments. If you do this, you will get a very clear picture.