Cómo agregar un número de secuencia para grupos en una consulta SQL sin tablas temporales

Datos de muestra

create table sometable([group] varchar(10), id int, somedata int)
insert sometable select 'Horses', 9, 11
insert sometable select 'chickens', 19, 121
insert sometable select 'Horses', 29, 123
insert sometable select 'chickens', 49, 124
insert sometable select 'Cows', 98, 1
insert sometable select 'Horses', 99, 2

Consulta

select
    Record = ROW_NUMBER() over (order by [Group], id),
    [Group],
    GroupSequence = DENSE_RANK() over (order by [Group])
from sometable

Salida

Record               Group      GroupSequence
-------------------- ---------- --------------------
1                    chickens   1
2                    chickens   1
3                    Cows       2
4                    Horses     3
5                    Horses     3
6                    Horses     3