The Muster Rolls are full of transcription errors, and it is just possible that the name was transposed. John Myers of the 11th H is the only person with that name in the Light Brigade, details on him were:
? Myers, Pte John, (1409), 11th H (p172) Bn in Farringdon [54-4-20], Berkshire. Enl 11-07-48 [54-4-20]. Prior Occ: Farmer [54-4-20]. At sea 2nd & 3rdMstrs [54-2-5]. At Varna 1st& 2nd Mstrs; sick 3rdMstr[54-3-5]. In Hosp at Balaclava 1stMstr [54-4-5]. Died 12-27-54 at Scut [54-4-5, 20]. Father, Thomas, Berks Co, Wallingford Parish [55-1-20]. Medal [393/400] w/ A [393/400], B , I [393/400], & S  Clasps.
Terry Brighton lists "known chargers" in his book (as do I in mine), but this is because not everyone who charged is known. There were between 607 and 678 men in the Charge ((see, years later we cannot be sure of even this)), and only about 530 chargers have been reasonably positively established. The fact that Myers was there (as indicated by the award of a Balaclava Clasp) means he was a possible charger, but no other evidence has surfaced to establish it one way or the other. Over 800 men received B Clasps---again, more than rode in the Charge..
A Faustian riddle,
Lawrence W. Crider Author, In Search of the Light Brigade Editor, The War Correspondent: the journal of the Crimean War Research Society