Generally I say, every dancer may count like he individually is able to recall the steps he wants to dance. So he may even count "boom, boom, doub di dooo, doub di dooo". But it's also worth to think about what the teacher counts to the pupil. At first, there are the Laird technique with "QQ QaQ QaQ" and the ISTD with the same. This count is the standard for professional examinations. Now for teaching the instructor may decide to follow this or might use other counting methods (sometimes I use different for the same figure, depending on WHAT I want to explain.) I agree that the often used "1,2 3a4 3a4" [I hope with 'a' and not with "and"] is a little bit strange because "pseudo-beats" are used to hide the problem of dancing SIX beats at a 4/4 time signature. Your method (step numbers) could be used for a situation when the teacher wants to refer to single steps for many times in his explanations, e.g. "at step 5 the lady has to be already slightly in advance to the man". BUT I don't use that step number count, because many people are not able to count the right rhythm, especially the quarter beats. So to cover all these problems most of the time I count for the people something like "rock, step, chas-sé-step chas-sé-step" (of course in German, but here in translation). This shows I often try to find a count that combines the action and the rhythm, as this is possible.