My opinion remains the same, the banner and the BSB are a waste of points. How many points are you playing at? By the time you buy the Tomb Herald, upgrade him to BSB, buy the banner and give him his mount, you're looking at a cool 135pts!!
- That's a Casket of Souls right there
- That's the majority of the cost of a Liche High Priest
- That's the majority of the cost of a Hierotitan.
Of those selections, I sure as heck wouldn't be going for the Tomb Herald BSB with Standard of the Undying Legion. You're essentially paying 135 points for a near defenseless level 0 wizard with one spell. You could pretty much pick up an extra 3 Ushabti for that cost in order to soak up the damage... and they don't suck up valuable power dice.
Also, it's an all your eggs in a single basket type approach. The 18 strong unit of Ushabti already costs 900 points. 30 more for command. That is already quite the points commitment, but then you have to add 135 more for the BSB. That's a lot of points in a slow moving unit that can easily be redirected, while the rest of your army is pieced up.
If you want to protect the unit, you have Neru's incantation of protection (which is cast by your level 4!). Or Pha's Protection. Or even Birona's Timewarp to get them into combat sooner.
That said, this is only my personal opinion. If you like the BSB+banner, then you should definitely field it. Give it a try and maybe it works out for you. People have different play-styles, strategies and list preferences. All I can say is that if it were me, I wouldn't field it.