Given my reading of the RFI... 80km hr road speed, max range 450km. This automatically disqualifies tracked SPGs.
Of the non tracked versions the best is arguably the RCH 155 which takes the turret of the Panzerhabuite 2000 and puts it either on a Boxer or a Piranha 10x10. It can fire while on the move and shoots 9 rounds a minute with an autoloader.
Archer would be my second pick.
If I was forced to choose only between those two I would agree if only for the reason that the Brits picked up Archer as an immediate stopgap after sending their AS 90s to Ukraine, but eventually selected RCH155. I'd want it on a LAV 10x10 chassis though for vehicle compatibility with our LAV fleet.
The number of only 2 individuals required per RCH/Piranha is incredible. Our entire ask of 80-98 could be handled by less than 200 individuals for operate/fire the units.
Don't believe everything you read about the number of crew. You need two folks to deploy and fire and RCH 155 but a whole hockey sock of folks to handle ammo resupply and forward support. The M777 is a particulalry personnel hungry gun requiring a crew of ten. That's 40 folks serving the four guns currently in a Canadian howitzer battery. That's basically the same number that manned the six-guns on an M109 gun line (i.e 6 guns x 7 pers - leaving aside CPs, recce, FOOs, CSS etc)
The advertised 2-man crew for the RCH 155 is nonsense. That is what it may take to move and fire a gun with a full magazine, but it won't give you 24/7 operation nor provide you with the necessary ammunition handling capability needed. You still need around 7 gun numbers. My guess is that a Canadian battery, as currently configured could probably operate two three-gun troops with the PYs that they currently have.
A Canadian artillery regiment is currently configured at around 552 PYs and 102 ARes positions. That mans two four-gun batteries with the PYs alone, but two six-gun batteries with their ARes augmentees.
As is, the regiment could probably man 12 x RCH 155s with their PYs alone.
To add the third six-gun battery would require appx 115 extra PYs or ARes positions (not counting the BC, FSCC, and FOOs who already exist for a third battery).
IMHO the regiment could probably harvest some 50-60 PYs internally by turning the STA battery into a troop that is part of the HQs bty, however, my preferred solution is to keep the STA battery and its 146 PYs/ARes positions but re-rolled as a loitering munitions general support battery by reducing the STA elements to a single troop and adding two troops of loitering munition launchers/controllers.
Long story short, I think there is a roadmap whereby the existing PYs in a CS regiment can be converted from an 8-gun M777 regiment to an 18-gun RCH 15 and loitering munitions regiment with the addition of as little as 60 - 115 ARes part-time positions.
