Light Emitting Decorations are almost always rated in INITIAL lumens even though many of them depreciate a ton like metal halide. Wording like "brighter" is possibly just an excuse for inadequate performance. High kelvin temps will appear "brighter" at lower illumination levels (like in night light or street lighting levels) whether they're LEDs or 6500K fluorescent. Glaring surface brightness also increases the perception of bright if the fixtures are within line of sight. A 1600 lm clear 100W light bulb will look much brighter than a five inch globe bulb putting out the same number of lumens when you look at the bulb.
You'll notice that HID and fluorescent systems are always designed using the MEAN lumens. It's a huge point of contention as fluorescent lamps have a much lower lamp lumen depreciation than LEDs, yet LED lighting is often done in "brand new out of the box lumens". Out with the offensive assumptions and awaiting glorious objective data. You didn't provide measured values from properly calibrated light meter or a drawing of uniformity of lighting. You said 5 lamps x 2? that's quite uncommon. You sure they were not 4 x 2 = 8 lamps?
The mirror reflector fixtures are usually pushing around 90% downward delivery.
http://www.visual-3d.com/tools/photometricViewer/default.aspx?id=18603
This is a 2007 publication so we have a good portrayal of what was available eight years ago.
http://www.gelighting.com/LightingWeb/ind/images/GE_lfl_lamps_t5_wm_ho_sell_sheet_tcm288-37367.pdf
Lithonia FGB164 4 54T5HO T1X20 + eight General Electric 51W F54T5/841/WM/ECO gets delivered output of 36,000 lumens down the bottom new and 33,000 maintained using 432W input to drive 8 lamps. 93 LPW x 90% fixture x 90% LLD gets you 83.7LPW start and 75.3 LPW maintained. Many T5 ballasts officially permit partial lamp operation.
L70 for LED was chosen as the life for the argument "30% drop is hardly noticeable to people". If you step dim to 50% measured output, it will appear 71% as bright. The much more preferable solution is to produce light to the needed illumination level using a source with minimal depreciation so it
maintains this level without the need for over illumination or a high level of power boost compensation.
If brand new LEDs are only matching existing fluorescent lamps, they're falling behind unless the rated life is based on L90 rather than the unreasonable L70.