To your basic question of is there any kind of splitter that will allow both to work without large losses the answer is no, there is not. A splitter is dividing power, particularly on transmit this is going to be very noticeable, losses will not be "larger" on transmit than receive, but transmit is where it will likely be most apparent.
The TS2k has separate antenna jacks on the back panel for each band, HF/6M, 2M, and 70cm. As the V2000 is a single feed 6M/2M/70cm antenna I assume you are doing something like assigning HF below 6M to HF Ant 1 jack and 6M to HF Ant 2 jack, and then using say a "triplexer" to combine the HF Ant 2 jack, 2M jack, and 70 cm jack into a single feedline to go to the V2000. Then the HF antenna (80M loop) is connected directly to HF Ant 1 jack.
In addition you want the AR5000 to be able to use the same two antennas for receive, having the TS2k and AR5000 in parallel on both antennas for receive purposes and muting and the AR5000 (and switching away the antenna) during TS2k transmit. Since the AR5000 also has 2 antenna ports you will not have to combine the 80M loop and the V2000 feedline for the use of the AR5000.
The power divider on each of the two antenna feeds that allows both the TS2k and the AR5000 is going to exhibit at least 3 dB of loss for each radio, at best (this means your 100 Watt TS2k just became a 50 Watt radio, at best, and probably more like 35 Watts). And to tell the truth I am not really sure one exist off-the-shelf that will work at the power levels you want, and if it does exist it will probably be a commercial unit, with the associated cost. The reason one might not exist is probably because this is not a very good idea from an equipment life standpoint. And the coax switch you point out probably does not have enough isolation by itself, you might want to add a second coax switch in each line that takes the AR5000 input to ground when the TS2k transmits. The spec sheet says 50 dB isolation in HF and less than that in VHF/UHF, that means that your 100 Watt TS2k (+50 dBm) will be whacking the front end of your AR 5000 with say +0 to +13 dBm, or more than 130 dB above its noise floor, if the switch is working at its best, and I have often found those kinds of switches to decrease in isolation over time. A honking big signal for the AR5000, maybe not enough to hurt it, but I would not be too sure.
It is mostly a poor practice to have wideband receive equipment attached to the same feedline as transmit equipment, particularly with only an antenna switch before the RX equipment and not some kind of sequencer and additional RX protection. Yes, I know that separate receivers and transmitters on a single feedline/antenna were common in the earlier days of amateur radio, I did it often myself. But the probability of a failure or incorrect switch setting with what you are describing is fairly high, and I can almost guarantee you transmitting 100 Watts out of the TS2k into the front end of the AR5000 one time by accident will cause problems.
What you want to achieve could be done, but you might have to build a few pieces/parts yourself to do it. Personally I would not try to make this happen. I would use separate antennas for the TS2k and the AR5000, and I still might (depending on how much and what kind of antenna separation you can achieve) include antenna switching in front of the AR5000 to kill the RX when the TS2k was transmitting.
There is certainly no off-the-shelf answer that I have seen recently that will be effective, simple, inexpensive, and dependable.
T!
