I was wondering why AB does not allow the techmarine in a Thunderfire unit to recruit servitors. On Page 73 of the SM codex, it says under the stat line for the techmarine "Each Thunderfire Cannon is crewed by a single Techmarine (see page 71 for special rules)." So it's clear that the "Techmarine" in the Thunderfire unit is a Techmarine per the codex and the Servitor entry on the Army list says on page 138: "You may inclue one unit of Servitors for every techmarine or master of the forge in your army".
The only argument that seems to have any grounding that I've read is based on the Thunderfire Army list entry on page 142 - that argument relies on the entry listing the unit composition as being "1 Techmarine GUNNER". However that seems to be a lot of nit picking given what the Thunderfire cannon description I quoted above on page 73 says.
If not allowing the Techmarine in the Thunderfire cannon to hire servitors is on purpose, why has the decision been made to ignore the age 73 description?
Note: I think it's clear that if a Servitor unit could be recruited, they operate under mindlock until the cannon is destroyed and the Techmarine gains the IC rule - so this isn't really a question about whether or not this is a "competitive" build or not - just that it seems strange that the option isn't there.
Thanks for all the support on the 40K list!
Greg