From: east coast, usa
... the [German] 150mm howitzer's organic to the HQ units have a range of 1 and isn't really condusive to attacking that way.
The 150mm howitzer in the German Hq's is meant to represent the 150mm sFH18, but the database stats for the 150mm howitzer more resemble a 150mm Infantry Gun. The '150mm Gun' in the database is a closer match to the 150mm sFH18, and the Gun has a range of 2.
If anyone has done a mod of this scenario and is interested in swapping the Howitzer for the Gun, you could do it manually one unit at a time. Or you could use the F4/F5 function. To do this, open the scenario in the editor, go to 'Edit' - 'Deployment', then 'Edit' - 'Forces', then hit F4 and Dump the OOB Text as a text file. Open that text file and use the 'Find and Replace With' function to replace all the '150mm Howitzer' slots with the '150mm Gun' equipment. Save the file, go back to the Editor and open the scenario, go to 'Edit' - 'Deployment', then 'Edit' - 'Forces', then hit F5 and 'Read' your new saved OOB Text file into the scenario.
Note : doing something like this unit by unit will avoid any possible adverse side effects, and sometimes 'Find and Replace' isn't much faster anyway.