I say companion types because they were obviously struck simultaneously.
There are four denarius types that pass from BRIT to FEL and then on to GERM.
Two of those types are dated.
Hercules standing: 141 coins in Reka Devnia with BRIT, namely 49 with TR P XV and 92 with TR P XVI; 24 with FEL, all TR P XVI; and 20 with GERM, namely 3 with TR P XVI and 17 with TR P XVII.
Serapis standing: 147 coins with BRIT, namely 65 with TR P XV and 82 with TR P XVI; 13 with FEL, all TR P XVI; and 22 with GERM, namely 8 with TR P XVI and 14 with TR P XVII.
Plus two undated types.
MARTI PROPVGNATORI: 170 coins with BRIT, 14 with FEL, 22 with GERM.
MONETA AVG: 135 coins with BRIT, 16 with FEL, 24 with GERM.
Can there be any doubt that these four types were strictly contemporaneous, and that each was struck in about the same volume?
There was a fifth contemporaneous type also, or rather apparently a sequence of three types: PROFECTIO AVG with BRIT, TR P XVI Libertas with BRIT and FEL, and INDVLGENTIA AVG with GERM. Plus Julia Domna's type DIANA LVCIFERA, represented by 210 coins in RD, compared with 185 dated Hercules, 182 dated Serapis, 206 Mars, 175 Moneta, and 154 sequence of three types.
Philip Hill, as usual, made a complete mess of this issue!