kristofera,
It is not a silly question. All navigation aids must be regarded as aids not gospel. It is always necessary to maintain simple common sense checks like 10,000 feet per 30 Nms. (plus or minus a bit) and at 10Nms from touch-down you should be at or around 3000 feet. These gross error checks work and one needs to use ALL available sources.
And as RAT5 has pointed out, what is the Rad Alt for?