Basing from WHFB to AOS questions

[swarmofseals]

I have a bunch of armies in the works, some of which are naturally based on rounds, some I need to convert from squares to rounds, and some are unbased and I need to figure out which bases to use. I also love using scenic bases, sometimes premade resin ones. 

I'm wondering if there is an official or semi-official conversion chart. I expect to see more tournaments requiring or rewarding rounds, so I'd like to try to get it right. I've been using the chart at http://havoc.holywarsgt.com/wp-content/uploads/2016/04/Warhammer-base-size-chart-V1.pdf, but some of the conversions are leaving me scratching my head. For example, why are Necropolis Knights on 70x105mm bases while Skeleton Chariots are on 95x120? 95x120 seems insanely huge for chariots, and both of these models were on the same sized square base. Would I run into trouble basing Chariots on 70x105? 

Also, while I've had decent results with bases from Proxie Models, they are missing some key sizes (particularly the larger bases). I'm thinking about ordering these from litko or aliexpress, the former being wood and the latter being MDF. 

Do any of you have experience sculpting greenstuff onto wood or MDF? Would love to know if this is a viable option.

Thanks in advance!

[TheOtherJosh]

70x105 is For larger single model units, like Drycha Hamadreth. The Snake Riders would fit into that category. They're bigger than the Large Cavalry (i.e. Juggernaut/Dracoth) (which are on 90mm ovals) but smaller than Chariots.

92x120 is the size for most of the chariots. (It's a good size for the Herald on Burning Chariot as an example, and the Slaves to Darkness Chariot is that size base.

(And many tournaments have been using the base sizes we have on TGA.)

[swarmofseals]

36 minutes ago, TheOtherJosh said:

70x105 is For larger single model units, like Drycha Hamadreth. The Snake Riders would fit into that category. They're bigger than the Large Cavalry (i.e. Juggernaut/Dracoth) (which are on 90mm ovals) but smaller than Chariots.

92x120 is the size for most of the chariots. (It's a good size for the Herald on Burning Chariot as an example, and the Slaves to Darkness Chariot is that size base.

(And many tournaments have been using the base sizes we have on TGA.)

Ahh, yeah. The Tomb Kings Chariots are a bit smaller than most and are fielded in increments of 3 rather than single model. It would make more sense for them to be on a slightly smaller base.

I didn't see the TGA basing guide; I'll look for it again.

EDIT: Found it, the google doc makes a LOT more sense!