No reason not to. Pretty much all industrial source I came across also states that E400H is not as reliable as the B5LH. Note that I am not staying it is not reliable, it's just that the B5LH was doing surprising well operationally right from the off (97% vs 98+%).
In real life both are doing very similar fuel consumption and reliability that there is very little to choose between. However, for the Euro 6 version, the B5LH will have about 500kg less weight that the E400H(MMC), so it will remain to be seen if this may upset the balance slightly.
No reason not to. Pretty much all industrial source I came across also states that E400H is not as reliable as the B5LH. Note that I am not staying it is not reliable, it's just that the B5LH was do ...