I'm not sure this would be unrealistic either. Given artillery assetts which are exclusively tasked to support you (all arty in CM seems to be handled this way), they would not have the usual excuse of being too busy helping someone else to be constantly laid on a target. If the delay effectively simulates ranging procedures then this could be avoided by having pre-registered points (only in scenarios where there had been sufficient time pre-game to do this). The arty would then simply wait for the signal and boom. While on this, it would be nice to be able to call in box and creeping barrages instead of just concentrations - and to specify more varieties of ammo - like incendiary or shrapnel (where historically issued).
Michael