punted for a couple of MM just to have an idea and then did some maths with the supposedly 1/150 ish AMC action scene kits that I've got... and the spiffy F-Toys at 1/144
AT-AT
RL 2000cm long
AMC 12cm long (1/166)
F-Toys 13.8cm long (1/144)
TIE Bomber
RL 780cm long
MM 2.7cm long (1/289)
F-Toys 5.4cm (1/144)
Imperial Shuttle
RL 2000cm long
MM 3cm long (1/666) to match the MM fighters it would need to be 7cm
F-Toys 13.8cm (1/144) although it can't be same scale as the TIE's as it's a similar size when seen in pics
Millenium Falcon
RL 3475cm long
AMC 14.5cm long (1/239) way out
sigh...