Pre-Battle Mother Russia roll & Artillery

Hi everyone !
Can a Horse ART or Guard Foot Art be reinforced by a Pre-Battle Mother Russia roll with a cannon or flag ?
We had the case last evening playing "Crossing the Berezina" when my opponent Guillaume (aka The Butcher) wanted to reinforce in Horse Artillery and didn't encounter the 4th block to complete his unit.
After reading another time the rules, we didn't see something about non basic Foot Artillery, so we decided to not let him reinforce his unit.
So, were we wrong or right ?
Thanks for an answer
Greetings from Le Mans & good Easter week end for everyone

Only the Foot Artillery get the reinforcement block with MR roll, if you read the Charts and if you look, that only additional blocks for FA are available

See example Picture with red arrow and red underline

Once again, Thanks a lot Michael for your rules mastering.