and you do have arty. ostheer doesnt get tiger and elefant and osttruppen and mortar ht and ... and ... and ... non doctrinal. if brits can get a t0 light vehicle, why doesn't ostheer get t0 paks or schrecks? "oh but you have fausts!" - yeah, if you're stupid enough to drive your bren into grens AND lose it afterwards because you sent it in unsupported, maybe you deserve to lose it. just like with emplacements etc. if you dont support it, you deserve to lose it. the base arty is, i admit, rather ineffective. but also inexpensive. and dropping that arty does force the enemy to reposition at the very least.
or, you know what... sure, you can get a mobile mortar... but instead you can't build centaur. or churchill.
every faction has some strengths and weaknesses. if you take away the weaknesses, you are left with only strengths... which is never good for balance.
edit: or, to pick up a recent thread: EVERY OTHER faction gets free green cover, why not ostheer?
i'm fairly certain that if you argue for brit indirect fire, you also argue against ostheer green cover. so whenever you ask yourself why brits don't have great non-doctrinal indirect fire, ask yourself why ostheer doesn't have green cover... same reason.
Cause arty is the only weakness of brits...