What makes you think that you know better than those who, with the benefit of experience, have decided that these bridge strike plates are justified and that the response shown on them is the best one?
The one and only (thankfully) bridge strike that I have been directly involved with was only reported to the emergency services initially, who then passed it onto our Control, who in turn passed it onto me. At some point during the process, the engineers' line reference was missed out, and the whole thing became very confusing (there are two bridges, on different lines, with the same number under the control of the box in question). I'd estimate that it cost an extra two or three minutes, which would have made the difference between getting the approaching train stopped or having it run onto the potentially damaged bridge, had it not been running a few minutes late. Our Control know, without really thinking about it, the informationt that they need to obtain from the caller, and can quickly act upon it. The emergency services, through no fault of their own, are less well placed to deal with that information, and in particular prompting the caller for information that hasn't been provided. In London, how would they know whether to pass the information onto Network Rail or London Underground?