Banks' analysts please wake up

What is it with banks' sellside analysts and the focus on the Tier 1 ratio or Core Tier 1 ratio as a measure of capital adequacy? I read this stuff and despair..

Take the example of say Beta Bank and Gamma Bank. Both have $1 of equity. Beta borrows $2 of debt and invests $1 in the UST market and lends $1 to Monopoly Electric Co. Gamma borrows $9,999 and invests $9,999 in the UST market and lends $1 to Monopoly Electric Co. The UST assets of both balance sheets, according to the Basel metrics, have a zero weight, while let's assume that the loans to Monpoly have 100% weighting. In other words, both banks have the same Core Tier 1 ratio.

But are they leveraged in the same way from the point of view of stockholders? Obviously not. Both banks earn OIS on their UST assets but pay LIBOR on their borrowings and - given LIBOR spreads over OIS - it is obvious that the earnings of Gamma are likely to be significantly more volatile than those of Beta. Even if Gamma has a higher ROE than Beta, how can it command a premium rating over Beta if they both earn the same returns on loans for Monopoly Electric Co? 

It shouldn't. So come on guys, take a closer look at the drivers of the volatility .