Western Digital MFM Controller(s) on AT systems.

I have a WD1006-WAH & WD1003V-MM2 mfm hard drive controllers. I have the WD Products text file from their old BBS (Feb 1989), my question is about the "high speed AT systems" which WD says is 10 to 16Mhz, does this actually mean these cards will not run in higher speed ISA systems like a 386 25mhz? PRODUCTS FOR AT SYSTEMS HARD DISK CONTROLLERS FOR MFM HARD DISK DRIVES - NO FLOPPY SUPPORT WD1006-WAH , feature F001R - Hard disk controller card with an ST506/ST412 interface. It supports 2 MFM drives with up to 16 heads and 2048 cylinders, 1:1 interleave. HARD DISK CONTROLLERS FOR MFM HARD DISK DRIVES AND FLOPPY DISK DRIVES WD1003V-MM2, feature F300R - Hard disk controller card with an ST506/ST412 interface. It supports a maximum of 2 MFM drives with up to 16 heads and 2048 cylinders at 2:1 interleave, and 2 floppy disk drives (5-1/4" 360K, 1.2Mb; 3-1/2" 720K, 1.44Mb). The "V" boards can run in high speed AT systems, (10 to 16 megahertz system speed). All I have for pre 16Mhz is an 80186 8 Mhz but it doesn't have ISA slots, some odd-ball convergent technologies bus, I tried these cards in a 486 DX2 80 so that is why I'm asking about the high speed AT systems. -John