The BT source material tells us that all 'Mechs are between 8 and 14 meters tall.
This would mean that the smallest 'Mechs (e.g.
Flea,
Locust) are around 8 meters (~26.25 feet) tall while the tallest 'Mechs (e.g.
Atlas,
Annihilator) are around 14 meters (~45.93 feet) tall.
In other words, the smallest 'Mechs are
supposed to be just over half the height of the largest 'Mechs.
The BattleTech
Centurion, a very humanoid 50-ton 'Mech, would be on the order of about 10 meters (~32.81 feet) tall if we take the entire head assembly to be about the same size as a large
[color="#b27204"]BMC Mini[/color] (~3.30 meters long x ~1.39 meters wide x 1.34 meters tall)) and use normal human proportions - a mere two meters (~6.56 feet) taller than the smallest of 'Mechs (which it outweighs by a factor of 2.5, while only being ~25% taller) and four meters (~13.12 feet) shorter than the largest of 'Mechs (which outweigh it by a factor of 2, while being only ~40% taller).
Riley Elf (larger Mini-type car - estimated size of
Centurion head assembly)
By comparison, the M1 Abrams MBT masses 61.3 metric tons (~23% heavier than the
Centurion, and only 1.3 tons heavier than the
Dragon and
Quickdraw) and has a hull length of 7.93 meters (26 feet), a width of 3.66 meters (12 feet), and a height of 2.89 meters (9.47 feet).
For MWO, the
Atlas is ~17.6 meters (~57.74 feet) tall - a ~26% increase over the canonical height.
For MWO, the
Centurion is ~14.7 meters (~48.23 feet) tall - a ~47% increase over the estimated canonical height.
If the
Centurion were re-scaled relative to the
Atlas (that is, 26% taller than its BT height), it would be on the order of 12.6 meters tall (the same as the current height of the MWO
Cicada).
By contrast, if the
Atlas were re-scaled relative to the
Centurion (that is, 47% taller than its BT height), it would be on the order of 20.58 meters tall (about 17% taller than it is now).
A MWO
Flea made to the same scale as the MWO
Centurion would be on the order of 11.76 meters tall (slightly taller than the current height of the MWO
Raven), while a MWO
Flea made to the same scale as the MWO
Atlas would be on the order of 10.08 meters tall (about midway between the heights of the MWO
Jenner and the MWO
Raven).
Most likely (IMO), the MWO
Flea and MWO
Locust will simply be set to "between 8.0 (the canonical lower bound for BattleMech height) and 9.4 meters (the height of the MWO
Jenner) tall".